Before last commit, memory compaction only migrates order-0 folios and
skips >0 order folios. Last commit splits all >0 order folios during
compaction. This commit migrates >0 order folios during compaction by
keeping isolated free pages at their original size without splitting them
into order-0 pages and using them directly during migration process.
What is different from the prior implementation:
1. All isolated free pages are kept in a NR_PAGE_ORDERS array of page
lists, where each page list stores free pages in the same order.
2. All free pages are not post_alloc_hook() processed nor buddy pages,
although their orders are stored in first page's private like buddy
pages.
3. During migration, in new page allocation time (i.e., in
compaction_alloc()), free pages are then processed by post_alloc_hook().
When migration fails and a new page is returned (i.e., in
compaction_free()), free pages are restored by reversing the
post_alloc_hook() operations using newly added
free_pages_prepare_fpi_none().
Step 3 is done for a latter optimization that splitting and/or merging
free pages during compaction becomes easier.
Note: without splitting free pages, compaction can end prematurely due to
migration will return -ENOMEM even if there is free pages. This happens
when no order-0 free page exist and compaction_alloc() return NULL.
Link: https://lkml.kernel.org/r/20240220183220.1451315-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Adam Manzanares <a.manzanares@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Enable >0 order folio memory compaction", v7.
This patchset enables >0 order folio memory compaction, which is one of
the prerequisitions for large folio support[1].
I am aware of that split free pages is necessary for folio migration in
compaction, since if >0 order free pages are never split and no order-0
free page is scanned, compaction will end prematurely due to migration
returns -ENOMEM. Free page split becomes a must instead of an
optimization.
lkp ncompare results (on a 8-CPU (Intel Xeon E5-2650 v4 @2.20GHz) 16G VM)
for default LRU (-no-mglru) and CONFIG_LRU_GEN are shown at the bottom,
copied from V3[4]. In sum, most of vm-scalability applications do not see
performance change, and the others see ~4% to ~26% performance boost under
default LRU and ~2% to ~6% performance boost under CONFIG_LRU_GEN.
Overview
===
To support >0 order folio compaction, the patchset changes how free pages
used for migration are kept during compaction. Free pages used to be
split into order-0 pages that are post allocation processed (i.e.,
PageBuddy flag cleared, page order stored in page->private is zeroed, and
page reference is set to 1). Now all free pages are kept in a
NR_PAGE_ORDER array of page lists based on their order without post
allocation process. When migrate_pages() asks for a new page, one of the
free pages, based on the requested page order, is then processed and given
out. And THP <2MB would need this feature.
[1] https://lore.kernel.org/linux-mm/f8d47176-03a8-99bf-a813-b5942830fd73@arm.com/
[2] https://lore.kernel.org/linux-mm/20231113170157.280181-1-zi.yan@sent.com/
[3] https://lore.kernel.org/linux-mm/20240123034636.1095672-1-zi.yan@sent.com/
[4] https://lore.kernel.org/linux-mm/20240202161554.565023-1-zi.yan@sent.com/
[5] https://lore.kernel.org/linux-mm/20240212163510.859822-1-zi.yan@sent.com/
[6] https://lore.kernel.org/linux-mm/20240214220420.1229173-1-zi.yan@sent.com/
[7] https://lore.kernel.org/linux-mm/20240216170432.1268753-1-zi.yan@sent.com/
This patch (of 4):
Commit 0a54864f8d ("kasan: remove PG_skip_kasan_poison flag") removes
the use of fpi_flags in should_skip_kasan_poison() and fpi_flags is only
passed to should_skip_kasan_poison() in free_pages_prepare(). Remove the
unused parameter.
Link: https://lkml.kernel.org/r/20240220183220.1451315-1-zi.yan@sent.com
Link: https://lkml.kernel.org/r/20240220183220.1451315-2-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Adam Manzanares <a.manzanares@samsung.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For each CPU hotplug event, we will update per-CPU data slice size and
corresponding PCP configuration for every online CPU to make the
implementation simple. But, Kyle reported that this takes tens seconds
during boot on a machine with 34 zones and 3840 CPUs.
So, in this patch, for each CPU hotplug event, we only update per-CPU data
slice size and corresponding PCP configuration for the CPUs that share
caches with the hotplugged CPU. With the patch, the system boot time
reduces 67 seconds on the machine.
Link: https://lkml.kernel.org/r/20240126081944.414520-1-ying.huang@intel.com
Fixes: 362d37a106 ("mm, pcp: reduce lock contention for draining high-order pages")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Originally-by: Kyle Meyer <kyle.meyer@hpe.com>
Reported-and-tested-by: Kyle Meyer <kyle.meyer@hpe.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Core & protocols
----------------
- Analyze and reorganize core networking structs (socks, netdev,
netns, mibs) to optimize cacheline consumption and set up
build time warnings to safeguard against future header changes.
This improves TCP performances with many concurrent connections
up to 40%.
- Add page-pool netlink-based introspection, exposing the
memory usage and recycling stats. This helps indentify
bad PP users and possible leaks.
- Refine TCP/DCCP source port selection to no longer favor even
source port at connect() time when IP_LOCAL_PORT_RANGE is set.
This lowers the time taken by connect() for hosts having
many active connections to the same destination.
- Refactor the TCP bind conflict code, shrinking related socket
structs.
- Refactor TCP SYN-Cookie handling, as a preparation step to
allow arbitrary SYN-Cookie processing via eBPF.
- Tune optmem_max for 0-copy usage, increasing the default value
to 128KB and namespecifying it.
- Allow coalescing for cloned skbs coming from page pools, improving
RX performances with some common configurations.
- Reduce extension header parsing overhead at GRO time.
- Add bridge MDB bulk deletion support, allowing user-space to
request the deletion of matching entries.
- Reorder nftables struct members, to keep data accessed by the
datapath first.
- Introduce TC block ports tracking and use. This allows supporting
multicast-like behavior at the TC layer.
- Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
classifiers (RSVP and tcindex).
- More data-race annotations.
- Extend the diag interface to dump TCP bound-only sockets.
- Conditional notification of events for TC qdisc class and actions.
- Support for WPAN dynamic associations with nearby devices, to form
a sub-network using a specific PAN ID.
- Implement SMCv2.1 virtual ISM device support.
- Add support for Batman-avd mulicast packet type.
BPF
---
- Tons of verifier improvements:
- BPF register bounds logic and range support along with a large
test suite
- log improvements
- complete precision tracking support for register spills
- track aligned STACK_ZERO cases as imprecise spilled registers. It
improves the verifier "instructions processed" metric from single
digit to 50-60% for some programs
- support for user's global BPF subprogram arguments with few
commonly requested annotations for a better developer experience
- support tracking of BPF_JNE which helps cases when the compiler
transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
like
- several fixes
- Add initial TX metadata implementation for AF_XDP with support in
mlx5 and stmmac drivers. Two types of offloads are supported right
now, that is, TX timestamp and TX checksum offload.
- Fix kCFI bugs in BPF all forms of indirect calls from BPF into
kernel and from kernel into BPF work with CFI enabled. This allows
BPF to work with CONFIG_FINEIBT=y.
- Change BPF verifier logic to validate global subprograms lazily
instead of unconditionally before the main program, so they can be
guarded using BPF CO-RE techniques.
- Support uid/gid options when mounting bpffs.
- Add a new kfunc which acquires the associated cgroup of a task
within a specific cgroup v1 hierarchy where the latter is identified
by its id.
- Extend verifier to allow bpf_refcount_acquire() of a map value field
obtained via direct load which is a use-case needed in sched_ext.
- Add BPF link_info support for uprobe multi link along with bpftool
integration for the latter.
- Support for VLAN tag in XDP hints.
- Remove deprecated bpfilter kernel leftovers given the project
is developed in user-space (https://github.com/facebook/bpfilter).
Misc
----
- Support for parellel TC self-tests execution.
- Increase MPTCP self-tests coverage.
- Updated the bridge documentation, including several so-far
undocumented features.
- Convert all the net self-tests to run in unique netns, to
avoid random failures due to conflict and allow concurrent
runs.
- Add TCP-AO self-tests.
- Add kunit tests for both cfg80211 and mac80211.
- Autogenerate Netlink families documentation from YAML spec.
- Add yml-gen support for fixed headers and recursive nests, the
tool can now generate user-space code for all genetlink families
for which we have specs.
- A bunch of additional module descriptions fixes.
- Catch incorrect freeing of pages belonging to a page pool.
Driver API
----------
- Rust abstractions for network PHY drivers; do not cover yet the
full C API, but already allow implementing functional PHY drivers
in rust.
- Introduce queue and NAPI support in the netdev Netlink interface,
allowing complete access to the device <> NAPIs <> queues
relationship.
- Introduce notifications filtering for devlink to allow control
application scale to thousands of instances.
- Improve PHY validation, requesting rate matching information for
each ethtool link mode supported by both the PHY and host.
- Add support for ethtool symmetric-xor RSS hash.
- ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
platform.
- Expose pin fractional frequency offset value over new DPLL generic
netlink attribute.
- Convert older drivers to platform remove callback returning void.
- Add support for PHY package MMD read/write.
New hardware / drivers
----------------------
- Ethernet:
- Octeon CN10K devices
- Broadcom 5760X P7
- Qualcomm SM8550 SoC
- Texas Instrument DP83TG720S PHY
- Bluetooth:
- IMC Networks Bluetooth radio
Removed
-------
- WiFi:
- libertas 16-bit PCMCIA support
- Atmel at76c50x drivers
- HostAP ISA/PCMCIA style 802.11b driver
- zd1201 802.11b USB dongles
- Orinoco ISA/PCMCIA 802.11b driver
- Aviator/Raytheon driver
- Planet WL3501 driver
- RNDIS USB 802.11b driver
Drivers
-------
- Ethernet high-speed NICs:
- Intel (100G, ice, idpf):
- allow one by one port representors creation and removal
- add temperature and clock information reporting
- add get/set for ethtool's header split ringparam
- add again FW logging
- adds support switchdev hardware packet mirroring
- iavf: implement symmetric-xor RSS hash
- igc: add support for concurrent physical and free-running timers
- i40e: increase the allowable descriptors
- nVidia/Mellanox:
- Preparation for Socket-Direct multi-dev netdev. That will allow
in future releases combining multiple PFs devices attached to
different NUMA nodes under the same netdev
- Broadcom (bnxt):
- TX completion handling improvements
- add basic ntuple filter support
- reduce MSIX vectors usage for MQPRIO offload
- add VXLAN support, USO offload and TX coalesce completion for P7
- Marvell Octeon EP:
- xmit-more support
- add PF-VF mailbox support and use it for FW notifications for VFs
- Wangxun (ngbe/txgbe):
- implement ethtool functions to operate pause param, ring param,
coalesce channel number and msglevel
- Netronome/Corigine (nfp):
- add flow-steering support
- support UDP segmentation offload
- Ethernet NICs embedded, slower, virtual:
- Xilinx AXI: remove duplicate DMA code adopting the dma engine driver
- stmmac: add support for HW-accelerated VLAN stripping
- TI AM654x sw: add mqprio, frame preemption & coalescing
- gve: add support for non-4k page sizes.
- virtio-net: support dynamic coalescing moderation
- nVidia/Mellanox Ethernet datacenter switches:
- allow firmware upgrade without a reboot
- more flexible support for bridge flooding via the compressed
FID flooding mode
- Ethernet embedded switches:
- Microchip:
- fine-tune flow control and speed configurations in KSZ8xxx
- KSZ88X3: enable setting rmii reference
- Renesas:
- add jumbo frames support
- Marvell:
- 88E6xxx: add "eth-mac" and "rmon" stats support
- Ethernet PHYs:
- aquantia: add firmware load support
- at803x: refactor the driver to simplify adding support for more
chip variants
- NXP C45 TJA11xx: Add MACsec offload support
- Wifi:
- MediaTek (mt76):
- NVMEM EEPROM improvements
- mt7996 Extremely High Throughput (EHT) improvements
- mt7996 Wireless Ethernet Dispatcher (WED) support
- mt7996 36-bit DMA support
- Qualcomm (ath12k):
- support for a single MSI vector
- WCN7850: support AP mode
- Intel (iwlwifi):
- new debugfs file fw_dbg_clear
- allow concurrent P2P operation on DFS channels
- Bluetooth:
- QCA2066: support HFP offload
- ISO: more broadcast-related improvements
- NXP: better recovery in case receiver/transmitter get out of sync
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"The most interesting thing is probably the networking structs
reorganization and a significant amount of changes is around
self-tests.
Core & protocols:
- Analyze and reorganize core networking structs (socks, netdev,
netns, mibs) to optimize cacheline consumption and set up build
time warnings to safeguard against future header changes
This improves TCP performances with many concurrent connections up
to 40%
- Add page-pool netlink-based introspection, exposing the memory
usage and recycling stats. This helps indentify bad PP users and
possible leaks
- Refine TCP/DCCP source port selection to no longer favor even
source port at connect() time when IP_LOCAL_PORT_RANGE is set. This
lowers the time taken by connect() for hosts having many active
connections to the same destination
- Refactor the TCP bind conflict code, shrinking related socket
structs
- Refactor TCP SYN-Cookie handling, as a preparation step to allow
arbitrary SYN-Cookie processing via eBPF
- Tune optmem_max for 0-copy usage, increasing the default value to
128KB and namespecifying it
- Allow coalescing for cloned skbs coming from page pools, improving
RX performances with some common configurations
- Reduce extension header parsing overhead at GRO time
- Add bridge MDB bulk deletion support, allowing user-space to
request the deletion of matching entries
- Reorder nftables struct members, to keep data accessed by the
datapath first
- Introduce TC block ports tracking and use. This allows supporting
multicast-like behavior at the TC layer
- Remove UAPI support for retired TC qdiscs (dsmark, CBQ and ATM) and
classifiers (RSVP and tcindex)
- More data-race annotations
- Extend the diag interface to dump TCP bound-only sockets
- Conditional notification of events for TC qdisc class and actions
- Support for WPAN dynamic associations with nearby devices, to form
a sub-network using a specific PAN ID
- Implement SMCv2.1 virtual ISM device support
- Add support for Batman-avd mulicast packet type
BPF:
- Tons of verifier improvements:
- BPF register bounds logic and range support along with a large
test suite
- log improvements
- complete precision tracking support for register spills
- track aligned STACK_ZERO cases as imprecise spilled registers.
This improves the verifier "instructions processed" metric from
single digit to 50-60% for some programs
- support for user's global BPF subprogram arguments with few
commonly requested annotations for a better developer
experience
- support tracking of BPF_JNE which helps cases when the compiler
transforms (unsigned) "a > 0" into "if a == 0 goto xxx" and the
like
- several fixes
- Add initial TX metadata implementation for AF_XDP with support in
mlx5 and stmmac drivers. Two types of offloads are supported right
now, that is, TX timestamp and TX checksum offload
- Fix kCFI bugs in BPF all forms of indirect calls from BPF into
kernel and from kernel into BPF work with CFI enabled. This allows
BPF to work with CONFIG_FINEIBT=y
- Change BPF verifier logic to validate global subprograms lazily
instead of unconditionally before the main program, so they can be
guarded using BPF CO-RE techniques
- Support uid/gid options when mounting bpffs
- Add a new kfunc which acquires the associated cgroup of a task
within a specific cgroup v1 hierarchy where the latter is
identified by its id
- Extend verifier to allow bpf_refcount_acquire() of a map value
field obtained via direct load which is a use-case needed in
sched_ext
- Add BPF link_info support for uprobe multi link along with bpftool
integration for the latter
- Support for VLAN tag in XDP hints
- Remove deprecated bpfilter kernel leftovers given the project is
developed in user-space (https://github.com/facebook/bpfilter)
Misc:
- Support for parellel TC self-tests execution
- Increase MPTCP self-tests coverage
- Updated the bridge documentation, including several so-far
undocumented features
- Convert all the net self-tests to run in unique netns, to avoid
random failures due to conflict and allow concurrent runs
- Add TCP-AO self-tests
- Add kunit tests for both cfg80211 and mac80211
- Autogenerate Netlink families documentation from YAML spec
- Add yml-gen support for fixed headers and recursive nests, the tool
can now generate user-space code for all genetlink families for
which we have specs
- A bunch of additional module descriptions fixes
- Catch incorrect freeing of pages belonging to a page pool
Driver API:
- Rust abstractions for network PHY drivers; do not cover yet the
full C API, but already allow implementing functional PHY drivers
in rust
- Introduce queue and NAPI support in the netdev Netlink interface,
allowing complete access to the device <> NAPIs <> queues
relationship
- Introduce notifications filtering for devlink to allow control
application scale to thousands of instances
- Improve PHY validation, requesting rate matching information for
each ethtool link mode supported by both the PHY and host
- Add support for ethtool symmetric-xor RSS hash
- ACPI based Wifi band RFI (WBRF) mitigation feature for the AMD
platform
- Expose pin fractional frequency offset value over new DPLL generic
netlink attribute
- Convert older drivers to platform remove callback returning void
- Add support for PHY package MMD read/write
New hardware / drivers:
- Ethernet:
- Octeon CN10K devices
- Broadcom 5760X P7
- Qualcomm SM8550 SoC
- Texas Instrument DP83TG720S PHY
- Bluetooth:
- IMC Networks Bluetooth radio
Removed:
- WiFi:
- libertas 16-bit PCMCIA support
- Atmel at76c50x drivers
- HostAP ISA/PCMCIA style 802.11b driver
- zd1201 802.11b USB dongles
- Orinoco ISA/PCMCIA 802.11b driver
- Aviator/Raytheon driver
- Planet WL3501 driver
- RNDIS USB 802.11b driver
Driver updates:
- Ethernet high-speed NICs:
- Intel (100G, ice, idpf):
- allow one by one port representors creation and removal
- add temperature and clock information reporting
- add get/set for ethtool's header split ringparam
- add again FW logging
- adds support switchdev hardware packet mirroring
- iavf: implement symmetric-xor RSS hash
- igc: add support for concurrent physical and free-running
timers
- i40e: increase the allowable descriptors
- nVidia/Mellanox:
- Preparation for Socket-Direct multi-dev netdev. That will
allow in future releases combining multiple PFs devices
attached to different NUMA nodes under the same netdev
- Broadcom (bnxt):
- TX completion handling improvements
- add basic ntuple filter support
- reduce MSIX vectors usage for MQPRIO offload
- add VXLAN support, USO offload and TX coalesce completion
for P7
- Marvell Octeon EP:
- xmit-more support
- add PF-VF mailbox support and use it for FW notifications
for VFs
- Wangxun (ngbe/txgbe):
- implement ethtool functions to operate pause param, ring
param, coalesce channel number and msglevel
- Netronome/Corigine (nfp):
- add flow-steering support
- support UDP segmentation offload
- Ethernet NICs embedded, slower, virtual:
- Xilinx AXI: remove duplicate DMA code adopting the dma engine
driver
- stmmac: add support for HW-accelerated VLAN stripping
- TI AM654x sw: add mqprio, frame preemption & coalescing
- gve: add support for non-4k page sizes.
- virtio-net: support dynamic coalescing moderation
- nVidia/Mellanox Ethernet datacenter switches:
- allow firmware upgrade without a reboot
- more flexible support for bridge flooding via the compressed
FID flooding mode
- Ethernet embedded switches:
- Microchip:
- fine-tune flow control and speed configurations in KSZ8xxx
- KSZ88X3: enable setting rmii reference
- Renesas:
- add jumbo frames support
- Marvell:
- 88E6xxx: add "eth-mac" and "rmon" stats support
- Ethernet PHYs:
- aquantia: add firmware load support
- at803x: refactor the driver to simplify adding support for more
chip variants
- NXP C45 TJA11xx: Add MACsec offload support
- Wifi:
- MediaTek (mt76):
- NVMEM EEPROM improvements
- mt7996 Extremely High Throughput (EHT) improvements
- mt7996 Wireless Ethernet Dispatcher (WED) support
- mt7996 36-bit DMA support
- Qualcomm (ath12k):
- support for a single MSI vector
- WCN7850: support AP mode
- Intel (iwlwifi):
- new debugfs file fw_dbg_clear
- allow concurrent P2P operation on DFS channels
- Bluetooth:
- QCA2066: support HFP offload
- ISO: more broadcast-related improvements
- NXP: better recovery in case receiver/transmitter get out of sync"
* tag 'net-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1714 commits)
lan78xx: remove redundant statement in lan78xx_get_eee
lan743x: remove redundant statement in lan743x_ethtool_get_eee
bnxt_en: Fix RCU locking for ntuple filters in bnxt_rx_flow_steer()
bnxt_en: Fix RCU locking for ntuple filters in bnxt_srxclsrldel()
bnxt_en: Remove unneeded variable in bnxt_hwrm_clear_vnic_filter()
tcp: Revert no longer abort SYN_SENT when receiving some ICMP
Revert "mlx5 updates 2023-12-20"
Revert "net: stmmac: Enable Per DMA Channel interrupt"
ipvlan: Remove usage of the deprecated ida_simple_xx() API
ipvlan: Fix a typo in a comment
net/sched: Remove ipt action tests
net: stmmac: Use interrupt mode INTM=1 for per channel irq
net: stmmac: Add support for TX/RX channel interrupt
net: stmmac: Make MSI interrupt routine generic
dt-bindings: net: snps,dwmac: per channel irq
net: phy: at803x: make read_status more generic
net: phy: at803x: add support for cdt cross short test for qca808x
net: phy: at803x: refactor qca808x cable test get status function
net: phy: at803x: generalize cdt fault length function
net: ethernet: cortina: Drop TSO support
...
commit 23baf831a3 ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive. This has caused
issues with code that was not yet upstream and depended on the previous
definition.
To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.
Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.
NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.
[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code.
This macro is provided by include/linux/kasan-tags.h, which does not
include any other headers, so it's safe to include it into mm.h without
causing circular include dependencies.
Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is redundant code in __free_pages_ok(). Use free_one_page()
simplify it.
Link: https://lkml.kernel.org/r/20231216030503.2126130-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__alloc_pages_direct_reclaim() is called from slowpath allocation where
high atomic reserves can be unreserved after there is a progress in
reclaim and yet no suitable page is found. Later should_reclaim_retry()
gets called from slow path allocation to decide if the reclaim needs to be
retried before OOM kill path is taken.
should_reclaim_retry() checks the available(reclaimable + free pages)
memory against the min wmark levels of a zone and returns:
a) true, if it is above the min wmark so that slow path allocation will
do the reclaim retries.
b) false, thus slowpath allocation takes oom kill path.
should_reclaim_retry() can also unreserves the high atomic reserves **but
only after all the reclaim retries are exhausted.**
In a case where there are almost none reclaimable memory and free pages
contains mostly the high atomic reserves but allocation context can't use
these high atomic reserves, makes the available memory below min wmark
levels hence false is returned from should_reclaim_retry() leading the
allocation request to take OOM kill path. This can turn into a early oom
kill if high atomic reserves are holding lot of free memory and
unreserving of them is not attempted.
(early)OOM is encountered on a VM with the below state:
[ 295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB
high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB
active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB
present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kB
local_pcp:492kB free_cma:0kB
[ 295.998656] lowmem_reserve[]: 0 32
[ 295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB
0*4096kB = 7752kB
Per above log, the free memory of ~7MB exist in the high atomic reserves
is not freed up before falling back to oom kill path.
Fix it by trying to unreserve the high atomic reserves in
should_reclaim_retry() before __alloc_pages_direct_reclaim() can fallback
to oom kill path.
Link: https://lkml.kernel.org/r/1700823445-27531-1-git-send-email-quic_charante@quicinc.com
Fixes: 0aaa29a56e ("mm, page_alloc: reserve pageblocks for high-order atomic allocations on demand")
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Reported-by: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Chris Goldsworthy <quic_cgoldswo@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Highatomic reserves are set to roughly 1% of zone for maximum and a
pageblock size for minimum. Encountered a system with the below
configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB
On such systems, even a single pageblock makes highatomic reserves are set
to ~8% of the zone memory. This high value can easily exert pressure on
the zone.
Per discussion with Michal and Mel, it is not much useful to reserve the
memory for highatomic allocations on such small systems[1]. Since the
minimum size for high atomic reserves is always going to be a pageblock
size and if 1% of zone managed pages is going to be below pageblock size,
don't reserve memory for high atomic allocations. Thanks Michal for this
suggestion[2].
Since no memory is being reserved for high atomic allocations and if
respective allocation failures are seen, this patch can be reverted.
[1] https://lore.kernel.org/linux-mm/20231117161956.d3yjdxhhm4rhl7h2@techsingularity.net/
[2] https://lore.kernel.org/linux-mm/ZVYRJMUitykepLRy@tiehlicka/
Link: https://lkml.kernel.org/r/c3a2a48e2cfe08176a80eaf01c110deb9e918055.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: page_alloc: fixes for high atomic reserve
caluculations", v3.
The state of the system where the issue exposed shown in oom kill logs:
[ 295.998653] Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB reserved_highatomic:8192KB active_anon:4kB inactive_anon:0kB active_file:24kB inactive_file:24kB unevictable:1220kB writepending:0kB present:70732kB managed:49224kB mlocked:0kB bounce:0kB free_pcp:688kBlocal_pcp:492kB free_cma:0kB
[ 295.998656] lowmem_reserve[]: 0 32
[ 295.998659] Normal: 508*4kB (UMEH) 241*8kB (UMEH) 143*16kB (UMEH)
33*32kB (UH) 7*64kB (UH) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 7752kB
From the above, it is seen that ~16MB of memory reserved for high atomic
reserves against the expectation of 1% reserves which is fixed in the 1st
patch.
Don't reserve the high atomic page blocks if 1% of zone memory size is
below a pageblock size.
This patch (of 2):
reserve_highatomic_pageblock() aims to reserve the 1% of the managed pages
of a zone, which is used for the high order atomic allocations.
It uses the below calculation to reserve:
static void reserve_highatomic_pageblock(struct page *page, ....) {
.......
max_managed = (zone_managed_pages(zone) / 100) + pageblock_nr_pages;
if (zone->nr_reserved_highatomic >= max_managed)
goto out;
zone->nr_reserved_highatomic += pageblock_nr_pages;
set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC);
move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL);
out:
....
}
Since we are always appending the 1% of zone managed pages count to
pageblock_nr_pages, the minimum it is turning into 2 pageblocks as the
nr_reserved_highatomic is incremented/decremented in pageblock sizes.
Encountered a system(actually a VM running on the Linux kernel) with the
below zone configuration:
Normal free:7728kB boost:0kB min:804kB low:1004kB high:1204kB
reserved_highatomic:8192KB managed:49224kB
The existing calculations making it to reserve the 8MB(with pageblock size
of 4MB) i.e. 16% of the zone managed memory. Reserving such high amount
of memory can easily exert memory pressure in the system thus may lead
into unnecessary reclaims till unreserving of high atomic reserves.
Since high atomic reserves are managed in pageblock size granules, as
MIGRATE_HIGHATOMIC is set for such pageblock, fix the calculations for
high atomic reserves as, minimum is pageblock size , maximum is
approximately 1% of the zone managed pages.
Link: https://lkml.kernel.org/r/cover.1700821416.git.quic_charante@quicinc.com
Link: https://lkml.kernel.org/r/1660034138397b82a0a8b6ae51cbe96bd583d89e.1700821416.git.quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The duplication makes it seem like some work is required before uncharging
in the !PageHWPoison case. But it isn't, so we can simplify the code a
little.
Note the PageMemcgKmem check is redundant, but I've left it in as it
avoids an unnecessary function call.
Link: https://lkml.kernel.org/r/20231108164920.3401565-1-jackmanb@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pages belonging to a page_pool (PP) instance must be freed through the
PP APIs in-order to correctly release any DMA mappings and release
refcnt on the DMA device when freeing PP instance. When PP release a
page (page_pool_release_page) the page->pp_magic value is cleared.
This patch detect a leaked PP page in free_page_is_bad() via
unexpected state of page->pp_magic value being PP_SIGNATURE.
We choose to report and treat it as a bad page. It would be possible
to release the page via returning it to the PP instance as the
page->pp pointer is likely still valid.
Notice this code is only activated when either compiled with
CONFIG_DEBUG_VM or boot cmdline debug_pagealloc=on, and
CONFIG_PAGE_POOL.
Reduced example output of leak with PP_SIGNATURE = dead000000000040:
BUG: Bad page state in process swapper/4 pfn:141fa6
page:000000006dbf8062 refcount:0 mapcount:0 mapping:0000000000000000 index:0x141fa6000 pfn:0x141fa6
flags: 0x2fffff80000000(node=0|zone=2|lastcpupid=0x1fffff)
page_type: 0xffffffff()
raw: 002fffff80000000 dead000000000040 ffff88814888a000 0000000000000000
raw: 0000000141fa6000 0000000000000001 00000000ffffffff 0000000000000000
page dumped because: page_pool leak
[...]
Call Trace:
<IRQ>
dump_stack_lvl+0x32/0x50
bad_page+0x70/0xf0
free_unref_page_prepare+0x263/0x430
free_unref_page+0x34/0x130
mlx5e_free_rx_mpwqe+0x190/0x1c0 [mlx5_core]
mlx5e_post_rx_mpwqes+0x1ac/0x280 [mlx5_core]
mlx5e_napi_poll+0x12b/0x710 [mlx5_core]
? skb_free_head+0x4f/0x90
__napi_poll+0x2b/0x1c0
net_rx_action+0x27b/0x360
The advantage is the Call Trace directly points to the function
leaking the PP page, which in this case is an on purpose bug
introduced into the mlx5 driver to test this code change.
Currently PP will periodically in page_pool_release_retry()
printk warning "stalled pool shutdown" which cannot be directly
corrolated to leaking and might as well be a false positive
due to SKBs being stuck on a socket for an extended period.
After this patch we should be able to remove this printk.
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
folio_prep_large_rmappable() is being used repeatedly along with a
conversion from page to folio, a check non-NULL, a check order > 1: wrap
it all up into struct folio *page_rmappable_folio(struct page *).
Link: https://lkml.kernel.org/r/8d92c6cf-eebe-748-e29c-c8ab224c741@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun heo <tj@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
For compound pages, the head sets the PG_head flag and the tail sets the
compound_head to indicate the head page. If a user allocates a compound
page and frees it with a different order, the compound page information
will not be properly initialized. To detect this problem,
compound_order(page) and the order argument are compared, but this is not
checked when the order argument is zero. That error should be checked
regardless of the order.
Link: https://lkml.kernel.org/r/20231023083217.1866451-1-hyesoo.yu@samsung.com
Signed-off-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "handle memoryless nodes more appropriately", v3.
Currently, in the process of initialization or offline memory, memoryless
nodes will still be built into the fallback list of itself or other nodes.
This is not what we expected, so this patch series removes memoryless
nodes from the fallback list entirely.
This patch (of 2):
In find_next_best_node(), we skipped the memoryless nodes when building
the zonelists of other normal nodes (N_NORMAL), but did not skip the
memoryless node itself when building the zonelist. This will cause it to
be traversed at runtime.
For example, say we have node0 and node1, node0 is memoryless
node, then the fallback order of node0 and node1 as follows:
[ 0.153005] Fallback order for Node 0: 0 1
[ 0.153564] Fallback order for Node 1: 1
After this patch, we skip memoryless node0 entirely, then
the fallback order of node0 and node1 as follows:
[ 0.155236] Fallback order for Node 0: 1
[ 0.155806] Fallback order for Node 1: 1
So it becomes completely invisible, which will reduce runtime
overhead.
And in this way, we will not try to allocate pages from memoryless node0,
then the panic mentioned in [1] will also be fixed. Even though this
problem has been solved by dropping the NODE_MIN_SIZE constrain in x86
[2], it would be better to fix it in core MM as well.
[1]. https://lore.kernel.org/all/20230212110305.93670-1-zhengqi.arch@bytedance.com/
[2]. https://lore.kernel.org/all/20231017062215.171670-1-rppt@kernel.org/
[zhengqi.arch@bytedance.com: update comment, per Ingo]
Link: https://lkml.kernel.org/r/7300fc00a057eefeb9a68c8ad28171c3f0ce66ce.1697799303.git.zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/cover.1697799303.git.zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/cover.1697711415.git.zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/157013e978468241de4a4c05d5337a44638ecb0e.1697711415.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In current PCP auto-tuning design, if the number of pages allocated is
much more than that of pages freed on a CPU, the PCP high may become the
maximal value even if the allocating/freeing depth is small, for example,
in the sender of network workloads. If a CPU was used as sender
originally, then it is used as receiver after context switching, we need
to fill the whole PCP with maximal high before triggering PCP draining for
consecutive high order freeing. This will hurt the performance of some
network workloads.
To solve the issue, in this patch, we will track the consecutive page
freeing with a counter in stead of relying on PCP draining. So, we can
detect consecutive page freeing much earlier.
On a 2-socket Intel server with 128 logical CPU, we tested
SCTP_STREAM_MANY test case of netperf test suite with 64-pair processes.
With the patch, the network bandwidth improves 5.0%. This restores the
performance drop caused by PCP auto-tuning.
Link: https://lkml.kernel.org/r/20231016053002.756205-10-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
One target of PCP is to minimize pages in PCP if the system free pages is
too few. To reach that target, when page reclaiming is active for the
zone (ZONE_RECLAIM_ACTIVE), we will stop increasing PCP high in allocating
path, decrease PCP high and free some pages in freeing path. But this may
be too late because the background page reclaiming may introduce latency
for some workloads. So, in this patch, during page allocation we will
detect whether the number of free pages of the zone is below high
watermark. If so, we will stop increasing PCP high in allocating path,
decrease PCP high and free some pages in freeing path. With this, we can
reduce the possibility of the premature background page reclaiming caused
by too large PCP.
The high watermark checking is done in allocating path to reduce the
overhead in hotter freeing path.
Link: https://lkml.kernel.org/r/20231016053002.756205-9-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The target to tune PCP high automatically is as follows,
- Minimize allocation/freeing from/to shared zone
- Minimize idle pages in PCP
- Minimize pages in PCP if the system free pages is too few
To reach these target, a tuning algorithm as follows is designed,
- When we refill PCP via allocating from the zone, increase PCP high.
Because if we had larger PCP, we could avoid to allocate from the
zone.
- In periodic vmstat updating kworker (via refresh_cpu_vm_stats()),
decrease PCP high to try to free possible idle PCP pages.
- When page reclaiming is active for the zone, stop increasing PCP
high in allocating path, decrease PCP high and free some pages in
freeing path.
So, the PCP high can be tuned to the page allocating/freeing depth of
workloads eventually.
One issue of the algorithm is that if the number of pages allocated is
much more than that of pages freed on a CPU, the PCP high may become the
maximal value even if the allocating/freeing depth is small. But this
isn't a severe issue, because there are no idle pages in this case.
One alternative choice is to increase PCP high when we drain PCP via
trying to free pages to the zone, but don't increase PCP high during PCP
refilling. This can avoid the issue above. But if the number of pages
allocated is much less than that of pages freed on a CPU, there will be
many idle pages in PCP and it is hard to free these idle pages.
1/8 (>> 3) of PCP high will be decreased periodically. The value 1/8 is
kind of arbitrary. Just to make sure that the idle PCP pages will be
freed eventually.
On a 2-socket Intel server with 224 logical CPU, we run 8 kbuild instances
in parallel (each with `make -j 28`) in 8 cgroup. This simulates the
kbuild server that is used by 0-Day kbuild service. With the patch, the
build time decreases 3.5%. The cycles% of the spinlock contention (mostly
for zone lock) decreases from 11.0% to 0.5%. The number of PCP draining
for high order pages freeing (free_high) decreases 65.6%. The number of
pages allocated from zone (instead of from PCP) decreases 83.9%.
Link: https://lkml.kernel.org/r/20231016053002.756205-8-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Suggested-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The page allocation performance requirements of different workloads are
usually different. So, we need to tune PCP (per-CPU pageset) high to
optimize the workload page allocation performance. Now, we have a system
wide sysctl knob (percpu_pagelist_high_fraction) to tune PCP high by hand.
But, it's hard to find out the best value by hand. And one global
configuration may not work best for the different workloads that run on
the same system. One solution to these issues is to tune PCP high of each
CPU automatically.
This patch adds the framework for PCP high auto-tuning. With it,
pcp->high of each CPU will be changed automatically by tuning algorithm at
runtime. The minimal high (pcp->high_min) is the original PCP high value
calculated based on the low watermark pages. While the maximal high
(pcp->high_max) is the PCP high value when percpu_pagelist_high_fraction
sysctl knob is set to MIN_PERCPU_PAGELIST_HIGH_FRACTION. That is, the
maximal pcp->high that can be set via sysctl knob by hand.
It's possible that PCP high auto-tuning doesn't work well for some
workloads. So, when PCP high is tuned by hand via the sysctl knob, the
auto-tuning will be disabled. The PCP high set by hand will be used
instead.
This patch only adds the framework, so pcp->high will be set to
pcp->high_min (original default) always. We will add actual auto-tuning
algorithm in the following patches in the series.
Link: https://lkml.kernel.org/r/20231016053002.756205-7-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When a task is allocating a large number of order-0 pages, it may acquire
the zone->lock multiple times allocating pages in batches. This may
unnecessarily contend on the zone lock when allocating very large number
of pages. This patch adapts the size of the batch based on the recent
pattern to scale the batch size for subsequent allocations.
On a 2-socket Intel server with 224 logical CPU, we run 8 kbuild instances
in parallel (each with `make -j 28`) in 8 cgroup. This simulates the
kbuild server that is used by 0-Day kbuild service. With the patch, the
cycles% of the spinlock contention (mostly for zone lock) decreases from
12.6% to 11.0% (with PCP size == 367).
Link: https://lkml.kernel.org/r/20231016053002.756205-6-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In page allocator, PCP (Per-CPU Pageset) is refilled and drained in
batches to increase page allocation throughput, reduce page
allocation/freeing latency per page, and reduce zone lock contention. But
too large batch size will cause too long maximal allocation/freeing
latency, which may punish arbitrary users. So the default batch size is
chosen carefully (in zone_batchsize(), the value is 63 for zone > 1GB) to
avoid that.
In commit 3b12e7e979 ("mm/page_alloc: scale the number of pages that are
batch freed"), the batch size will be scaled for large number of page
freeing to improve page freeing performance and reduce zone lock
contention. Similar optimization can be used for large number of pages
allocation too.
To find out a suitable max batch scale factor (that is, max effective
batch size), some tests and measurement on some machines were done as
follows.
A set of debug patches are implemented as follows,
- Set PCP high to be 2 * batch to reduce the effect of PCP high
- Disable free batch size scaling to get the raw performance.
- The code with zone lock held is extracted from rmqueue_bulk() and
free_pcppages_bulk() to 2 separate functions to make it easy to
measure the function run time with ftrace function_graph tracer.
- The batch size is hard coded to be 63 (default), 127, 255, 511,
1023, 2047, 4095.
Then will-it-scale/page_fault1 is used to generate the page
allocation/freeing workload. The page allocation/freeing throughput
(page/s) is measured via will-it-scale. The page allocation/freeing
average latency (alloc/free latency avg, in us) and allocation/freeing
latency at 99 percentile (alloc/free latency 99%, in us) are measured with
ftrace function_graph tracer.
The test results are as follows,
Sapphire Rapids Server
======================
Batch throughput free latency free latency alloc latency alloc latency
page/s avg / us 99% / us avg / us 99% / us
----- ---------- ------------ ------------ ------------- -------------
63 513633.4 2.33 3.57 2.67 6.83
127 517616.7 4.35 6.65 4.22 13.03
255 520822.8 8.29 13.32 7.52 25.24
511 524122.0 15.79 23.42 14.02 49.35
1023 525980.5 30.25 44.19 25.36 94.88
2047 526793.6 59.39 84.50 45.22 140.81
Ice Lake Server
===============
Batch throughput free latency free latency alloc latency alloc latency
page/s avg / us 99% / us avg / us 99% / us
----- ---------- ------------ ------------ ------------- -------------
63 620210.3 2.21 3.68 2.02 4.35
127 627003.0 4.09 6.86 3.51 8.28
255 630777.5 7.70 13.50 6.17 15.97
511 633651.5 14.85 22.62 11.66 31.08
1023 637071.1 28.55 42.02 20.81 54.36
2047 638089.7 56.54 84.06 39.28 91.68
Cascade Lake Server
===================
Batch throughput free latency free latency alloc latency alloc latency
page/s avg / us 99% / us avg / us 99% / us
----- ---------- ------------ ------------ ------------- -------------
63 404706.7 3.29 5.03 3.53 4.75
127 422475.2 6.12 9.09 6.36 8.76
255 411522.2 11.68 16.97 10.90 16.39
511 428124.1 22.54 31.28 19.86 32.25
1023 414718.4 43.39 62.52 40.00 66.33
2047 429848.7 86.64 120.34 71.14 106.08
Commet Lake Desktop
===================
Batch throughput free latency free latency alloc latency alloc latency
page/s avg / us 99% / us avg / us 99% / us
----- ---------- ------------ ------------ ------------- -------------
63 795183.13 2.18 3.55 2.03 3.05
127 803067.85 3.91 6.56 3.85 5.52
255 812771.10 7.35 10.80 7.14 10.20
511 817723.48 14.17 27.54 13.43 30.31
1023 818870.19 27.72 40.10 27.89 46.28
Coffee Lake Desktop
===================
Batch throughput free latency free latency alloc latency alloc latency
page/s avg / us 99% / us avg / us 99% / us
----- ---------- ------------ ------------ ------------- -------------
63 510542.8 3.13 4.40 2.48 3.43
127 514288.6 5.97 7.89 4.65 6.04
255 516889.7 11.86 15.58 8.96 12.55
511 519802.4 23.10 28.81 16.95 26.19
1023 520802.7 45.30 52.51 33.19 45.95
2047 519997.1 90.63 104.00 65.26 81.74
From the above data, to restrict the allocation/freeing latency to be less
than 100 us in most times, the max batch scale factor needs to be less
than or equal to 5.
Although it is reasonable to use 5 as max batch scale factor for the
systems tested, there are also slower systems. Where smaller value should
be used to constrain the page allocation/freeing latency.
So, in this patch, a new kconfig option (PCP_BATCH_SCALE_MAX) is added to
set the max batch scale factor. Whose default value is 5, and users can
reduce it when necessary.
Link: https://lkml.kernel.org/r/20231016053002.756205-5-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In commit f26b3fa046 ("mm/page_alloc: limit number of high-order pages
on PCP during bulk free"), the PCP (Per-CPU Pageset) will be drained when
PCP is mostly used for high-order pages freeing to improve the cache-hot
pages reusing between page allocating and freeing CPUs.
On system with small per-CPU data cache slice, pages shouldn't be cached
before draining to guarantee cache-hot. But on a system with large
per-CPU data cache slice, some pages can be cached before draining to
reduce zone lock contention.
So, in this patch, instead of draining without any caching, "pcp->batch"
pages will be cached in PCP before draining if the size of the per-CPU
data cache slice is more than "3 * batch".
In theory, if the size of per-CPU data cache slice is more than "2 *
batch", we can reuse cache-hot pages between CPUs. But considering the
other usage of cache (code, other data accessing, etc.), "3 * batch" is
used.
Note: "3 * batch" is chosen to make sure the optimization works on recent
x86_64 server CPUs. If you want to increase it, please check whether it
breaks the optimization.
On a 2-socket Intel server with 128 logical CPU, with the patch, the
network bandwidth of the UNIX (AF_UNIX) test case of lmbench test suite
with 16-pair processes increase 70.5%. The cycles% of the spinlock
contention (mostly for zone lock) decreases from 46.1% to 21.3%. The
number of PCP draining for high order pages freeing (free_high) decreases
89.9%. The cache miss rate keeps 0.2%.
Link: https://lkml.kernel.org/r/20231016053002.756205-4-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: PCP high auto-tuning", v3.
The page allocation performance requirements of different workloads are
often different. So, we need to tune the PCP (Per-CPU Pageset) high on
each CPU automatically to optimize the page allocation performance.
The list of patches in series is as follows,
[1/9] mm, pcp: avoid to drain PCP when process exit
[2/9] cacheinfo: calculate per-CPU data cache size
[3/9] mm, pcp: reduce lock contention for draining high-order pages
[4/9] mm: restrict the pcp batch scale factor to avoid too long latency
[5/9] mm, page_alloc: scale the number of pages that are batch allocated
[6/9] mm: add framework for PCP high auto-tuning
[7/9] mm: tune PCP high automatically
[8/9] mm, pcp: decrease PCP high if free pages < high watermark
[9/9] mm, pcp: reduce detecting time of consecutive high order page freeing
Patch [1/9], [2/9], [3/9] optimize the PCP draining for consecutive
high-order pages freeing.
Patch [4/9], [5/9] optimize batch freeing and allocating.
Patch [6/9], [7/9], [8/9] implement and optimize a PCP high
auto-tuning method.
Patch [9/9] optimize the PCP draining for consecutive high order page
freeing based on PCP high auto-tuning.
The test results for patches with performance impact are as follows,
kbuild
======
On a 2-socket Intel server with 224 logical CPU, we run 8 kbuild instances
in parallel (each with `make -j 28`) in 8 cgroup. This simulates the
kbuild server that is used by 0-Day kbuild service.
build time lock contend% free_high alloc_zone
---------- ---------- --------- ----------
base 100.0 14.0 100.0 100.0
patch1 99.5 12.8 19.5 95.6
patch3 99.4 12.6 7.1 95.6
patch5 98.6 11.0 8.1 97.1
patch7 95.1 0.5 2.8 15.6
patch9 95.0 1.0 8.8 20.0
The PCP draining optimization (patch [1/9], [3/9]) and PCP batch
allocation optimization (patch [5/9]) reduces zone lock contention a
little. The PCP high auto-tuning (patch [7/9], [9/9]) reduces build time
visibly. Where the tuning target: the number of pages allocated from zone
reduces greatly. So, the zone contention cycles% reduces greatly.
With PCP tuning patches (patch [7/9], [9/9]), the average used memory
during test increases up to 18.4% because more pages are cached in PCP.
But at the end of the test, the number of the used memory decreases to the
same level as that of the base patch. That is, the pages cached in PCP
will be released to zone after not being used actively.
netperf SCTP_STREAM_MANY
========================
On a 2-socket Intel server with 128 logical CPU, we tested
SCTP_STREAM_MANY test case of netperf test suite with 64-pair processes.
score lock contend% free_high alloc_zone cache miss rate%
----- ---------- --------- ---------- ----------------
base 100.0 2.1 100.0 100.0 1.3
patch1 99.4 2.1 99.4 99.4 1.3
patch3 106.4 1.3 13.3 106.3 1.3
patch5 106.0 1.2 13.2 105.9 1.3
patch7 103.4 1.9 6.7 90.3 7.6
patch9 108.6 1.3 13.7 108.6 1.3
The PCP draining optimization (patch [1/9]+[3/9]) improves performance.
The PCP high auto-tuning (patch [7/9]) reduces performance a little
because PCP draining cannot be triggered in time sometimes. So, the cache
miss rate% increases. The further PCP draining optimization (patch [9/9])
based on PCP tuning restore the performance.
lmbench3 UNIX (AF_UNIX)
=======================
On a 2-socket Intel server with 128 logical CPU, we tested UNIX
(AF_UNIX socket) test case of lmbench3 test suite with 16-pair
processes.
score lock contend% free_high alloc_zone cache miss rate%
----- ---------- --------- ---------- ----------------
base 100.0 51.4 100.0 100.0 0.2
patch1 116.8 46.1 69.5 104.3 0.2
patch3 199.1 21.3 7.0 104.9 0.2
patch5 200.0 20.8 7.1 106.9 0.3
patch7 191.6 19.9 6.8 103.8 2.8
patch9 193.4 21.7 7.0 104.7 2.1
The PCP draining optimization (patch [1/9], [3/9]) improves performance
much. The PCP tuning (patch [7/9]) reduces performance a little because
PCP draining cannot be triggered in time sometimes. The further PCP
draining optimization (patch [9/9]) based on PCP tuning restores the
performance partly.
The patchset adds several fields in struct per_cpu_pages. The struct
layout before/after the patchset is as follows,
base
====
struct per_cpu_pages {
spinlock_t lock; /* 0 4 */
int count; /* 4 4 */
int high; /* 8 4 */
int batch; /* 12 4 */
short int free_factor; /* 16 2 */
short int expire; /* 18 2 */
/* XXX 4 bytes hole, try to pack */
struct list_head lists[13]; /* 24 208 */
/* size: 256, cachelines: 4, members: 7 */
/* sum members: 228, holes: 1, sum holes: 4 */
/* padding: 24 */
} __attribute__((__aligned__(64)));
patched
=======
struct per_cpu_pages {
spinlock_t lock; /* 0 4 */
int count; /* 4 4 */
int high; /* 8 4 */
int high_min; /* 12 4 */
int high_max; /* 16 4 */
int batch; /* 20 4 */
u8 flags; /* 24 1 */
u8 alloc_factor; /* 25 1 */
u8 expire; /* 26 1 */
/* XXX 1 byte hole, try to pack */
short int free_count; /* 28 2 */
/* XXX 2 bytes hole, try to pack */
struct list_head lists[13]; /* 32 208 */
/* size: 256, cachelines: 4, members: 11 */
/* sum members: 237, holes: 2, sum holes: 3 */
/* padding: 16 */
} __attribute__((__aligned__(64)));
The size of the struct doesn't changed with the patchset.
This patch (of 9):
In commit f26b3fa046 ("mm/page_alloc: limit number of high-order pages
on PCP during bulk free"), the PCP (Per-CPU Pageset) will be drained when
PCP is mostly used for high-order pages freeing to improve the cache-hot
pages reusing between page allocation and freeing CPUs.
But, the PCP draining mechanism may be triggered unexpectedly when process
exits. With some customized trace point, it was found that PCP draining
(free_high == true) was triggered with the order-1 page freeing with the
following call stack,
=> free_unref_page_commit
=> free_unref_page
=> __mmdrop
=> exit_mm
=> do_exit
=> do_group_exit
=> __x64_sys_exit_group
=> do_syscall_64
Checking the source code, this is the page table PGD freeing
(mm_free_pgd()). It's a order-1 page freeing if
CONFIG_PAGE_TABLE_ISOLATION=y. Which is a common configuration for
security.
Just before that, page freeing with the following call stack was found,
=> free_unref_page_commit
=> free_unref_page_list
=> release_pages
=> tlb_batch_pages_flush
=> tlb_finish_mmu
=> exit_mmap
=> __mmput
=> exit_mm
=> do_exit
=> do_group_exit
=> __x64_sys_exit_group
=> do_syscall_64
So, when a process exits,
- a large number of user pages of the process will be freed without
page allocation, it's highly possible that pcp->free_factor becomes >
0. In fact, this is expected behavior to improve process exit
performance.
- after freeing all user pages, the PGD will be freed, which is a
order-1 page freeing, PCP will be drained.
All in all, when a process exits, it's high possible that the PCP will be
drained. This is an unexpected behavior.
To avoid this, in the patch, the PCP draining will only be triggered for 2
consecutive high-order page freeing.
On a 2-socket Intel server with 224 logical CPU, we run 8 kbuild instances
in parallel (each with `make -j 28`) in 8 cgroup. This simulates the
kbuild server that is used by 0-Day kbuild service. With the patch, the
cycles% of the spinlock contention (mostly for zone lock) decreases from
14.0% to 12.8% (with PCP size == 367). The number of PCP draining for
high order pages freeing (free_high) decreases 80.5%.
This helps network workload too for reduced zone lock contention. On a
2-socket Intel server with 128 logical CPU, with the patch, the network
bandwidth of the UNIX (AF_UNIX) test case of lmbench test suite with
16-pair processes increase 16.8%. The cycles% of the spinlock contention
(mostly for zone lock) decreases from 51.4% to 46.1%. The number of PCP
draining for high order pages freeing (free_high) decreases 30.5%. The
cache miss rate keeps 0.2%.
Link: https://lkml.kernel.org/r/20231016053002.756205-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20231016053002.756205-2-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The next_page is only used to forward page in case target is in second
half range. Move forward page directly to remove unnecessary next_page.
Link: https://lkml.kernel.org/r/20230927103514.98281-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Two minor cleanups to break_down_buddy_pages", v2.
Two minor cleanups to break_down_buddy_pages.
This patch (of 2):
1. We always have target in range started with next_page and full free
range started with current_buddy.
2. The last split range size is 1 << low and low should be >= 0, then
size >= 1. So page + size != page is always true (because size > 0).
As summary, current_page will not equal to target page.
Link: https://lkml.kernel.org/r/20230927103514.98281-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230927103514.98281-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When guard page debug is enabled and set_page_guard returns success, we
miss to forward page to point to start of next split range and we will do
split unexpectedly in page range without target page. Move start page
update before set_page_guard to fix this.
As we split to wrong target page, then splited pages are not able to merge
back to original order when target page is put back and splited pages
except target page is not usable. To be specific:
Consider target page is the third page in buddy page with order 2.
| buddy-2 | Page | Target | Page |
After break down to target page, we will only set first page to Guard
because of bug.
| Guard | Page | Target | Page |
When we try put_page_back_buddy with target page, the buddy page of target
if neither guard nor buddy, Then it's not able to construct original page
with order 2
| Guard | Page | buddy-0 | Page |
All pages except target page is not in free list and is not usable.
Link: https://lkml.kernel.org/r/20230927094401.68205-1-shikemeng@huaweicloud.com
Fixes: 06be6ff3d2 ("mm,hwpoison: rework soft offline for free pages")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 4b23a68f95 ("mm/page_alloc: protect PCP lists with a spinlock")
bypasses the pcplist on lock contention and returns the page directly to
the buddy list of the page's migratetype.
For pages that don't have their own pcplist, such as CMA and HIGHATOMIC,
the migratetype is temporarily updated such that the page can hitch a ride
on the MOVABLE pcplist. Their true type is later reassessed when flushing
in free_pcppages_bulk(). However, when lock contention is detected after
the type was already overridden, the bypass will then put the page on the
wrong buddy list.
Once on the MOVABLE buddy list, the page becomes eligible for fallbacks
and even stealing. In the case of HIGHATOMIC, otherwise ineligible
allocations can dip into the highatomic reserves. In the case of CMA, the
page can be lost from the CMA region permanently.
Use a separate pcpmigratetype variable for the pcplist override. Use the
original migratetype when going directly to the buddy. This fixes the bug
and should make the intentions more obvious in the code.
Originally sent here to address the HIGHATOMIC case:
https://lore.kernel.org/lkml/20230821183733.106619-4-hannes@cmpxchg.org/
Changelog updated in response to the CMA-specific bug report.
[mgorman@techsingularity.net: updated changelog]
Link: https://lkml.kernel.org/r/20230911181108.GA104295@cmpxchg.org
Fixes: 4b23a68f95 ("mm/page_alloc: protect PCP lists with a spinlock")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Joe Liu <joe.liu@mediatek.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In the past, movable allocations could be disallowed from CMA through
PF_MEMALLOC_PIN. As CMA pages are funneled through the MOVABLE pcplist,
this required filtering that cornercase during allocations, such that
pinnable allocations wouldn't accidentally get a CMA page.
However, since 8e3560d963 ("mm: honor PF_MEMALLOC_PIN for all movable
pages"), PF_MEMALLOC_PIN automatically excludes __GFP_MOVABLE. Once
again, MOVABLE implies CMA is allowed.
Remove the stale filtering code. Also remove a stale comment that was
introduced as part of the filtering code, because the filtering let
order-0 pages fall through to the buddy allocator. See 1d91df85f3
("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore}
APIs") for context. The comment's been obsolete since the introduction of
the explicit ALLOC_HIGHATOMIC flag in eb2e2b425c ("mm/page_alloc:
explicitly record high-order atomic allocations in alloc_flags").
Link: https://lkml.kernel.org/r/20230824153821.243148-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stored in the first tail page's flags, this flag replaces the destructor.
That removes the last of the destructors, so remove all references to
folio_dtor and compound_dtor.
Link: https://lkml.kernel.org/r/20230816151201.3655946-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We can use a bit in page[1].flags to indicate that this folio belongs to
hugetlb instead of using a value in page[1].dtors. That lets
folio_test_hugetlb() become an inline function like it should be. We can
also get rid of NULL_COMPOUND_DTOR.
Link: https://lkml.kernel.org/r/20230816151201.3655946-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The only remaining destructor is free_compound_page(). Inline it into
destroy_large_folio() and remove the array it used to live in.
Link: https://lkml.kernel.org/r/20230816151201.3655946-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Match folio_undo_large_rmappable(), and move the casting from page to
folio into the callers (which they were largely doing anyway).
Link: https://lkml.kernel.org/r/20230816151201.3655946-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Indirect calls are expensive, thanks to Spectre. Test for
TRANSHUGE_PAGE_DTOR and destroy the folio appropriately. Move the
free_compound_page() call into destroy_large_folio() to simplify later
patches.
Link: https://lkml.kernel.org/r/20230816151201.3655946-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pass a folio instead of the head page to save a few instructions. Update
the documentation, at least in English.
Link: https://lkml.kernel.org/r/20230816151201.3655946-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Indirect calls are expensive, thanks to Spectre. Call free_huge_page()
directly if the folio belongs to hugetlb.
Link: https://lkml.kernel.org/r/20230816151201.3655946-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We have get_pageblock_migratetype and get_pfnblock_migratetype to get
migratetype of page. get_pfnblock_migratetype accepts both page and pfn
from caller while get_pageblock_migratetype only accept page and get pfn
with page_to_pfn from page.
In case we already record pfn of page, we can simply call
get_pfnblock_migratetype to avoid a page_to_pfn.
Link: https://lkml.kernel.org/r/20230811115945.3423894-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Two minor cleanups for get pageblock migratetype".
This series contains two minor cleanups for get pageblock migratetype.
More details can be found in respective patches.
This patch (of 2):
get_pfnblock_flags_mask() just calls inline inner
__get_pfnblock_flags_mask without any extra work. Just opencode
__get_pfnblock_flags_mask in get_pfnblock_flags_mask and replace call to
__get_pfnblock_flags_mask with call to get_pfnblock_flags_mask to remove
unnecessary __get_pfnblock_flags_mask.
Link: https://lkml.kernel.org/r/20230811115945.3423894-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230811115945.3423894-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Just remove the redundant parameter alloc_order from
reserve_highatomic_pageblock(). No functional modification involved.
Link: https://lkml.kernel.org/r/20230809073323.1065286-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We get batch from pcp and just pass it to nr_pcp_free immediately. Get
batch from pcp inside nr_pcp_free to remove unnecessary parameter batch.
Link: https://lkml.kernel.org/r/20230809100754.3094517-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Two minor cleanups for pcp list in page_alloc".
There are two minor cleanups for pcp list in page_alloc. More details
can be found in respective patches.
This patch (of 2):
After commit fd56eef258 ("mm/page_alloc: simplify how many pages are
selected per pcp list during bulk free"), we will drain all pages in
selected pcp list. And we ensured passed count is < pcp->count. Then,
the search will finish before wrap-around and track of active PCP lists
range intended for wrap-around case is no longer needed.
Link: https://lkml.kernel.org/r/20230809100754.3094517-1-shikemeng@huaweicloud.com
Link: https://lkml.kernel.org/r/20230809100754.3094517-2-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit 5d0a661d80 ("mm/page_alloc: use only one PCP list for
THP-sized allocations"), local variable base is just as same as order. So
remove it. No functional change intended.
Link: https://lkml.kernel.org/r/20230803114934.693989-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When free_pages is 0, alike_pages is not used. So alike_pages calculation
can be avoided by checking free_pages early to save cpu cycles. Also fix
typo 'comparable'. It should be 'compatible' here.
Link: https://lkml.kernel.org/r/20230801123723.2225543-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If pfn is outside zone boundaries in the first round, ret will be set to
1. But if pfn is changed to inside the zone boundaries in zone span
seqretry path, ret is still set to 1 leading to false page outside zone
error info.
This is from code inspection. The race window should be really small thus
hard to trigger in real world.
[akpm@linux-foundation.org: code simplification, per Matthew]
Link: https://lkml.kernel.org/r/20230704111823.940331-1-linmiaohe@huawei.com
Fixes: bdc8cb9845 ("[PATCH] memory hotplug locking: zone span seqlock")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__build_all_zonelists() acquires zonelist_update_seq by first disabling
interrupts via local_irq_save() and then acquiring the seqlock with
write_seqlock(). This is troublesome and leads to problems on PREEMPT_RT.
The problem is that the inner spinlock_t becomes a sleeping lock on
PREEMPT_RT and must not be acquired with disabled interrupts.
The API provides write_seqlock_irqsave() which does the right thing in one
step. printk_deferred_enter() has to be invoked in non-migrate-able
context to ensure that deferred printing is enabled and disabled on the
same CPU. This is the case after zonelist_update_seq has been acquired.
There was discussion on the first submission that the order should be:
local_irq_disable();
printk_deferred_enter();
write_seqlock();
to avoid pitfalls like having an unaccounted printk() coming from
write_seqlock_irqsave() before printk_deferred_enter() is invoked. The
only origin of such a printk() can be a lockdep splat because the lockdep
annotation happens after the sequence count is incremented. This is
exceptional and subject to change.
It was also pointed that PREEMPT_RT can be affected by the printk problem
since its write_seqlock_irqsave() does not really disable interrupts.
This isn't the case because PREEMPT_RT's printk implementation differs
from the mainline implementation in two important aspects:
- Printing happens in a dedicated threads and not at during the
invocation of printk().
- In emergency cases where synchronous printing is used, a different
driver is used which does not use tty_port::lock.
Acquire zonelist_update_seq with write_seqlock_irqsave() and then defer
printk output.
Link: https://lkml.kernel.org/r/20230623201517.yw286Knb@linutronix.de
Fixes: 1007843a91 ("mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The current calculation of min_free_kbytes only uses ZONE_DMA and
ZONE_NORMAL pages,but the ZONE_MOVABLE zone->_watermark[WMARK_MIN] will
also divide part of min_free_kbytes.This will cause the min watermark of
ZONE_NORMAL to be too small in the presence of ZONE_MOVEABLE.
__GFP_HIGH and PF_MEMALLOC allocations usually don't need movable zone
pages, so just like ZONE_HIGHMEM, cap pages_min to a small value in
__setup_per_zone_wmarks().
On my testing machine with 16GB of memory (transparent hugepage is turned
off by default, and movablecore=12G is configured) The following is a
comparative test data of watermark_min
no patch add patch
ZONE_DMA 1 8
ZONE_DMA32 151 709
ZONE_NORMAL 233 1113
ZONE_MOVABLE 1434 128
min_free_kbytes 7288 7326
Link: https://lkml.kernel.org/r/20230625031656.23941-1-liuq131@chinatelecom.cn
Signed-off-by: liuq <liuq131@chinatelecom.cn>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- Yosry has also eliminated cgroup's atomic rstat flushing.
- Nhat Pham adds the new cachestat() syscall. It provides userspace
with the ability to query pagecache status - a similar concept to
mincore() but more powerful and with improved usability.
- Mel Gorman provides more optimizations for compaction, reducing the
prevalence of page rescanning.
- Lorenzo Stoakes has done some maintanance work on the get_user_pages()
interface.
- Liam Howlett continues with cleanups and maintenance work to the maple
tree code. Peng Zhang also does some work on maple tree.
- Johannes Weiner has done some cleanup work on the compaction code.
- David Hildenbrand has contributed additional selftests for
get_user_pages().
- Thomas Gleixner has contributed some maintenance and optimization work
for the vmalloc code.
- Baolin Wang has provided some compaction cleanups,
- SeongJae Park continues maintenance work on the DAMON code.
- Huang Ying has done some maintenance on the swap code's usage of
device refcounting.
- Christoph Hellwig has some cleanups for the filemap/directio code.
- Ryan Roberts provides two patch series which yield some
rationalization of the kernel's access to pte entries - use the provided
APIs rather than open-coding accesses.
- Lorenzo Stoakes has some fixes to the interaction between pagecache
and directio access to file mappings.
- John Hubbard has a series of fixes to the MM selftesting code.
- ZhangPeng continues the folio conversion campaign.
- Hugh Dickins has been working on the pagetable handling code, mainly
with a view to reducing the load on the mmap_lock.
- Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
128 to 8.
- Domenico Cerasuolo has improved the zswap reclaim mechanism by
reorganizing the LRU management.
- Matthew Wilcox provides some fixups to make gfs2 work better with the
buffer_head code.
- Vishal Moola also has done some folio conversion work.
- Matthew Wilcox has removed the remnants of the pagevec code - their
functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
- Yosry Ahmed brought back some cgroup v1 stats in OOM logs
- Yosry has also eliminated cgroup's atomic rstat flushing
- Nhat Pham adds the new cachestat() syscall. It provides userspace
with the ability to query pagecache status - a similar concept to
mincore() but more powerful and with improved usability
- Mel Gorman provides more optimizations for compaction, reducing the
prevalence of page rescanning
- Lorenzo Stoakes has done some maintanance work on the
get_user_pages() interface
- Liam Howlett continues with cleanups and maintenance work to the
maple tree code. Peng Zhang also does some work on maple tree
- Johannes Weiner has done some cleanup work on the compaction code
- David Hildenbrand has contributed additional selftests for
get_user_pages()
- Thomas Gleixner has contributed some maintenance and optimization
work for the vmalloc code
- Baolin Wang has provided some compaction cleanups,
- SeongJae Park continues maintenance work on the DAMON code
- Huang Ying has done some maintenance on the swap code's usage of
device refcounting
- Christoph Hellwig has some cleanups for the filemap/directio code
- Ryan Roberts provides two patch series which yield some
rationalization of the kernel's access to pte entries - use the
provided APIs rather than open-coding accesses
- Lorenzo Stoakes has some fixes to the interaction between pagecache
and directio access to file mappings
- John Hubbard has a series of fixes to the MM selftesting code
- ZhangPeng continues the folio conversion campaign
- Hugh Dickins has been working on the pagetable handling code, mainly
with a view to reducing the load on the mmap_lock
- Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
from 128 to 8
- Domenico Cerasuolo has improved the zswap reclaim mechanism by
reorganizing the LRU management
- Matthew Wilcox provides some fixups to make gfs2 work better with the
buffer_head code
- Vishal Moola also has done some folio conversion work
- Matthew Wilcox has removed the remnants of the pagevec code - their
functionality is migrated over to struct folio_batch
* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
mm/hugetlb: remove hugetlb_set_page_subpool()
mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
hugetlb: revert use of page_cache_next_miss()
Revert "page cache: fix page_cache_next/prev_miss off by one"
mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
mm: memcg: rename and document global_reclaim()
mm: kill [add|del]_page_to_lru_list()
mm: compaction: convert to use a folio in isolate_migratepages_block()
mm: zswap: fix double invalidate with exclusive loads
mm: remove unnecessary pagevec includes
mm: remove references to pagevec
mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
mm: remove struct pagevec
net: convert sunrpc from pagevec to folio_batch
i915: convert i915_gpu_error to use a folio_batch
pagevec: rename fbatch_count()
mm: remove check_move_unevictable_pages()
drm: convert drm_gem_put_pages() to use a folio_batch
i915: convert shmem_sg_free_table() to use a folio_batch
scatterlist: add sg_set_folio()
...
Commit bf75f20056 ("mm/page_alloc: add page->buddy_list and
page->pcp_list") introduces page->buddy_list and page->pcp_list as a union
with page->lru, but missed to change get_page_from_free_area() to use
page->buddy_list to clarify the correct type of list for a free page.
Link: https://lkml.kernel.org/r/7e7ab533247d40c0ea0373c18a6a48e5667f9e10.1687333557.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove some unneeded header files. No functional change intended.
Link: https://lkml.kernel.org/r/20230603112558.213694-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 73444bc4d8 ("mm, page_alloc: do not wake kswapd with zone lock
held") moved wakeup_kswapd() from steal_suitable_fallback() to rmqueue()
using ZONE_BOOSTED_WATERMARK flag.
Only allocation contexts that include ALLOC_KSWAPD (which corresponds to
__GFP_KSWAPD_RECLAIM) should wake kswapd, for callers are supposed to
remove __GFP_KSWAPD_RECLAIM if trying to hold pgdat->kswapd_wait has a
risk of deadlock. But since zone->flags is a shared variable, a thread
doing !__GFP_KSWAPD_RECLAIM allocation request might observe this flag
being set immediately after another thread doing __GFP_KSWAPD_RECLAIM
allocation request set this flag, causing possibility of deadlock.
Link: https://lkml.kernel.org/r/c3c3dacf-dd3b-77c9-f96a-d0982b4b2a4f@I-love.SAKURA.ne.jp
Fixes: 73444bc4d8 ("mm, page_alloc: do not wake kswapd with zone lock held")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The different branches for retry are unnecessarily complicated. There are
really only three outcomes: progress (retry n times), skipped (retry if
reclaim can help), failed (retry with higher priority).
Rearrange the branches and the retry counter to make it simpler.
[hannes@cmpxchg.org: restore behavior when hitting max_retries]
Link: https://lkml.kernel.org/r/20230602144705.GB161817@cmpxchg.org
Link: https://lkml.kernel.org/r/20230519123959.77335-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: compaction: cleanups & simplifications".
These compaction cleanups are split out from the huge page allocator
series[1], as requested by reviewer feedback.
[1] https://lore.kernel.org/linux-mm/20230418191313.268131-1-hannes@cmpxchg.org/
This patch (of 5):
The compaction result helpers encode quirks that are specific to the
allocator's retry logic. E.g. COMPACT_SUCCESS and COMPACT_COMPLETE
actually represent failures that should be retried upon, and so on. I
frequently found myself pulling up the helper implementation in order to
understand and work on the retry logic. They're not quite clean
abstractions; rather they split the retry logic into two locations.
Remove the helpers and inline the checks. Then comment on the result
interpretations directly where the decision making happens.
Link: https://lkml.kernel.org/r/20230519123959.77335-1-hannes@cmpxchg.org
Link: https://lkml.kernel.org/r/20230519123959.77335-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
smatch reports
mm/page_alloc.c:247:5: warning: symbol
'sysctl_lowmem_reserve_ratio' was not declared. Should it be static?
This variable is only used in its defining file, so it should be static
Link: https://lkml.kernel.org/r/20230518141119.927074-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The is_check_pages_enabled() only used in page_alloc.c, move it into
page_alloc.c, also use it in free_tail_page_prepare().
Link: https://lkml.kernel.org/r/20230516063821.121844-14-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This moves all page alloc related sysctls to its own file, as part of the
kernel/sysctl.c spring cleaning, also move some functions declarations
from mm.h into internal.h.
Link: https://lkml.kernel.org/r/20230516063821.121844-13-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pm_restrict_gfp_mask()/pm_restore_gfp_mask() only used in power, let's
move them out of page_alloc.c.
Adding a general gfp_has_io_fs() function which return true if gfp with
both __GFP_IO and __GFP_FS flags, then use it inside of
pm_suspended_storage(), also the pm_suspended_storage() is moved into
suspend.h.
Link: https://lkml.kernel.org/r/20230516063821.121844-11-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mark_free_page() is only used in kernel/power/snapshot.c, move it out
to reduce a bit of page_alloc.c
Link: https://lkml.kernel.org/r/20230516063821.121844-10-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move DEBUG_PAGEALLOC related functions into a single file to reduce a bit
of page_alloc.c.
Link: https://lkml.kernel.org/r/20230516063821.121844-9-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
... to a single file to reduce a bit of page_alloc.c.
Link: https://lkml.kernel.org/r/20230516063821.121844-8-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DEFINE_DYNAMIC_DEBUG_METADATA and DYNAMIC_DEBUG_BRANCH already has stub
definitions without dynamic debug feature, remove unnecessary
alloc_contig_dump_pages() stub.
Link: https://lkml.kernel.org/r/20230516063821.121844-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Squash the page_is_consistent() into bad_range() as there is only one
caller.
Link: https://lkml.kernel.org/r/20230516063821.121844-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Let's move show_mem.c from lib to mm, as it belongs memory subsystem, also
split some memory statistic related functions from page_alloc.c to
show_mem.c, and we cleanup some unneeded include.
There is no functional change.
Link: https://lkml.kernel.org/r/20230516063821.121844-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
set_zone_contiguous() is only used in mm init/hotplug, and
clear_zone_contiguous() only used in hotplug, move them from page_alloc.c
to the more appropriate file.
Link: https://lkml.kernel.org/r/20230516063821.121844-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit f2fc4b44ec ("mm: move init_mem_debugging_and_hardening() to
mm/mm_init.c"), the init_on_alloc() and init_on_free() define is better to
move there too.
Link: https://lkml.kernel.org/r/20230516063821.121844-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: page_alloc: misc cleanup and refactor", v2.
This aims to reduce more space in page_alloc.c, also do some cleanup, no
functional changes intended.
This patch (of 13):
Since commit 9420f89db2 ("mm: move most of core MM initialization to
mm/mm_init.c"), mirrored_kernelcore should be moved into mm_init.c, as
most related codes are already there.
Link: https://lkml.kernel.org/r/20230516063821.121844-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20230516063821.121844-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__pageblock_pfn_to_page() currently performs both pfn_valid check and
pfn_to_online_page(). The former one is redundant because the latter is a
stronger check. Drop pfn_valid().
Link: https://lkml.kernel.org/r/c3868b58c6714c09a43440d7d02c7b4eed6e03f6.1682342634.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
UEFI Specification version 2.9 introduces the concept of memory
acceptance. Some Virtual Machine platforms, such as Intel TDX or AMD
SEV-SNP, require memory to be accepted before it can be used by the
guest. Accepting happens via a protocol specific to the Virtual Machine
platform.
There are several ways the kernel can deal with unaccepted memory:
1. Accept all the memory during boot. It is easy to implement and it
doesn't have runtime cost once the system is booted. The downside is
very long boot time.
Accept can be parallelized to multiple CPUs to keep it manageable
(i.e. via DEFERRED_STRUCT_PAGE_INIT), but it tends to saturate
memory bandwidth and does not scale beyond the point.
2. Accept a block of memory on the first use. It requires more
infrastructure and changes in page allocator to make it work, but
it provides good boot time.
On-demand memory accept means latency spikes every time kernel steps
onto a new memory block. The spikes will go away once workload data
set size gets stabilized or all memory gets accepted.
3. Accept all memory in background. Introduce a thread (or multiple)
that gets memory accepted proactively. It will minimize time the
system experience latency spikes on memory allocation while keeping
low boot time.
This approach cannot function on its own. It is an extension of #2:
background memory acceptance requires functional scheduler, but the
page allocator may need to tap into unaccepted memory before that.
The downside of the approach is that these threads also steal CPU
cycles and memory bandwidth from the user's workload and may hurt
user experience.
Implement #1 and #2 for now. #2 is the default. Some workloads may want
to use #1 with accept_memory=eager in kernel command line. #3 can be
implemented later based on user's demands.
Support of unaccepted memory requires a few changes in core-mm code:
- memblock accepts memory on allocation. It serves early boot memory
allocations and doesn't limit them to pre-accepted pool of memory.
- page allocator accepts memory on the first allocation of the page.
When kernel runs out of accepted memory, it accepts memory until the
high watermark is reached. It helps to minimize fragmentation.
EFI code will provide two helpers if the platform supports unaccepted
memory:
- accept_memory() makes a range of physical addresses accepted.
- range_contains_unaccepted_memory() checks anything within the range
of physical addresses requires acceptance.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport <rppt@linux.ibm.com> # memblock
Link: https://lore.kernel.org/r/20230606142637.5171-2-kirill.shutemov@linux.intel.com
- Some KSM work from David Hildenbrand, to make the PR_SET_MEMORY_MERGE
ioctl's behavior more similar to KSM's behavior.
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Merge tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- Some DAMON cleanups from Kefeng Wang
- Some KSM work from David Hildenbrand, to make the PR_SET_MEMORY_MERGE
ioctl's behavior more similar to KSM's behavior.
[ Andrew called these "final", but I suspect we'll have a series fixing
up the fact that the last commit in the dmapools series in the
previous pull seems to have unintentionally just reverted all the
other commits in the same series.. - Linus ]
* tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: hwpoison: coredump: support recovery from dump_user_range()
mm/page_alloc: add some comments to explain the possible hole in __pageblock_pfn_to_page()
mm/ksm: move disabling KSM from s390/gmap code to KSM code
selftests/ksm: ksm_functional_tests: add prctl unmerge test
mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0
mm/damon/paddr: fix missing folio_sz update in damon_pa_young()
mm/damon/paddr: minor refactor of damon_pa_mark_accessed_or_deactivate()
mm/damon/paddr: minor refactor of damon_pa_pageout()
Now the __pageblock_pfn_to_page() is used by set_zone_contiguous(), which
checks whether the given zone contains holes, and uses
pfn_to_online_page() to validate if the start pfn is online and valid, as
well as using pfn_valid() to validate the end pfn.
However, the __pageblock_pfn_to_page() function may return non-NULL even
if the end pfn of a pageblock is in a memory hole in some situations. For
example, if the pageblock order is MAX_ORDER, which will fall into 2
sub-sections, and the end pfn of the pageblock may be hole even though the
start pfn is online and valid.
See below memory layout as an example and suppose the pageblock order is
MAX_ORDER.
[ 0.000000] Zone ranges:
[ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff]
[ 0.000000] DMA32 empty
[ 0.000000] Normal [mem 0x0000000100000000-0x0000001fa7ffffff]
[ 0.000000] Movable zone start for each node
[ 0.000000] Early memory node ranges
[ 0.000000] node 0: [mem 0x0000000040000000-0x0000001fa3c7ffff]
[ 0.000000] node 0: [mem 0x0000001fa3c80000-0x0000001fa3ffffff]
[ 0.000000] node 0: [mem 0x0000001fa4000000-0x0000001fa402ffff]
[ 0.000000] node 0: [mem 0x0000001fa4030000-0x0000001fa40effff]
[ 0.000000] node 0: [mem 0x0000001fa40f0000-0x0000001fa73cffff]
[ 0.000000] node 0: [mem 0x0000001fa73d0000-0x0000001fa745ffff]
[ 0.000000] node 0: [mem 0x0000001fa7460000-0x0000001fa746ffff]
[ 0.000000] node 0: [mem 0x0000001fa7470000-0x0000001fa758ffff]
[ 0.000000] node 0: [mem 0x0000001fa7590000-0x0000001fa7dfffff]
Focus on the last memory range, and there is a hole for the range [mem
0x0000001fa7590000-0x0000001fa7dfffff]. That means the last pageblock
will contain the range from 0x1fa7c00000 to 0x1fa7ffffff, since the
pageblock must be 4M aligned. And in this pageblock, these pfns will fall
into 2 sub-section (the sub-section size is 2M aligned).
So, the 1st sub-section (indicates pfn range: 0x1fa7c00000 - 0x1fa7dfffff
) in this pageblock is valid by calling subsection_map_init() in
free_area_init(), but the 2nd sub-section (indicates pfn range:
0x1fa7e00000 - 0x1fa7ffffff ) in this pageblock is not valid.
This did not break anything until now, but the zone continuous is fragile
in this possible scenario. So as previous discussion[1], it is better to
add some comments to explain this possible issue in case there are some
future pfn walkers that rely on this.
[1] https://lore.kernel.org/all/87r0sdsmr6.fsf@yhuang6-desk2.ccr.corp.intel.com/
Link: https://lkml.kernel.org/r/5c26368865e79c743a453dea48d30670b19d2e4f.1682425534.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/5c26368865e79c743a453dea48d30670b19d2e4f.1682425534.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* cpuset changes including the fix for an incorrect interaction with CPU
hotplug and an optimization.
* Other doc and cosmetic changes.
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Merge tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset changes including the fix for an incorrect interaction with
CPU hotplug and an optimization
- Other doc and cosmetic changes
* tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
docs: cgroup-v1/cpusets: update libcgroup project link
cgroup/cpuset: Minor updates to test_cpuset_prs.sh
cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated
cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset
cpuset: Clean up cpuset_node_allowed
cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers
Commit 700d2e9a36 ("mm, page_alloc: reduce page alloc/free sanity
checks") has introduced a new static key check_pages_enabled to control
when struct pages are sanity checked during allocation and freeing. Mel
Gorman suggested that free_tail_pages_check() could use this static key as
well, instead of relying on CONFIG_DEBUG_VM. That makes sense, so do
that. Also rename the function to free_tail_page_prepare() because it
works on a single tail page and has a struct page preparation component as
well as the optional checking component.
Also remove some unnecessary unlikely() within static_branch_unlikely()
statements that Mel pointed out for commit 700d2e9a36.
Link: https://lkml.kernel.org/r/20230405142840.11068-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexander Halbuer <halbuer@sra.uni-hannover.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A bug was reported by Yuanxi Liu where allocating 1G pages at runtime is
taking an excessive amount of time for large amounts of memory. Further
testing allocating huge pages that the cost is linear i.e. if allocating
1G pages in batches of 10 then the time to allocate nr_hugepages from
10->20->30->etc increases linearly even though 10 pages are allocated at
each step. Profiles indicated that much of the time is spent checking the
validity within already existing huge pages and then attempting a
migration that fails after isolating the range, draining pages and a whole
lot of other useless work.
Commit eb14d4eefd ("mm,page_alloc: drop unnecessary checks from
pfn_range_valid_contig") removed two checks, one which ignored huge pages
for contiguous allocations as huge pages can sometimes migrate. While
there may be value on migrating a 2M page to satisfy a 1G allocation, it's
potentially expensive if the 1G allocation fails and it's pointless to try
moving a 1G page for a new 1G allocation or scan the tail pages for valid
PFNs.
Reintroduce the PageHuge check and assume any contiguous region with
hugetlbfs pages is unsuitable for a new 1G allocation.
The hpagealloc test allocates huge pages in batches and reports the
average latency per page over time. This test happens just after boot
when fragmentation is not an issue. Units are in milliseconds.
hpagealloc
6.3.0-rc6 6.3.0-rc6 6.3.0-rc6
vanilla hugeallocrevert-v1r1 hugeallocsimple-v1r2
Min Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%)
1st-qrtle Latency 356.61 ( 0.00%) 5.34 ( 98.50%) 19.85 ( 94.43%)
2nd-qrtle Latency 697.26 ( 0.00%) 5.47 ( 99.22%) 20.44 ( 97.07%)
3rd-qrtle Latency 972.94 ( 0.00%) 5.50 ( 99.43%) 20.81 ( 97.86%)
Max-1 Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%)
Max-5 Latency 82.14 ( 0.00%) 5.11 ( 93.78%) 19.31 ( 76.49%)
Max-10 Latency 150.54 ( 0.00%) 5.20 ( 96.55%) 19.43 ( 87.09%)
Max-90 Latency 1164.45 ( 0.00%) 5.53 ( 99.52%) 20.97 ( 98.20%)
Max-95 Latency 1223.06 ( 0.00%) 5.55 ( 99.55%) 21.06 ( 98.28%)
Max-99 Latency 1278.67 ( 0.00%) 5.57 ( 99.56%) 22.56 ( 98.24%)
Max Latency 1310.90 ( 0.00%) 8.06 ( 99.39%) 26.62 ( 97.97%)
Amean Latency 678.36 ( 0.00%) 5.44 * 99.20%* 20.44 * 96.99%*
6.3.0-rc6 6.3.0-rc6 6.3.0-rc6
vanilla revert-v1 hugeallocfix-v2
Duration User 0.28 0.27 0.30
Duration System 808.66 17.77 35.99
Duration Elapsed 830.87 18.08 36.33
The vanilla kernel is poor, taking up to 1.3 second to allocate a huge
page and almost 10 minutes in total to run the test. Reverting the
problematic commit reduces it to 8ms at worst and the patch takes 26ms.
This patch fixes the main issue with skipping huge pages but leaves the
page_count() out because a page with an elevated count potentially can
migrate.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=217022
Link: https://lkml.kernel.org/r/20230414141429.pwgieuwluxwez3rj@techsingularity.net
Fixes: eb14d4eefd ("mm,page_alloc: drop unnecessary checks from pfn_range_valid_contig")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Yuanxi Liu <y.liu@naruida.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
syzbot is reporting circular locking dependency which involves
zonelist_update_seq seqlock [1], for this lock is checked by memory
allocation requests which do not need to be retried.
One deadlock scenario is kmalloc(GFP_ATOMIC) from an interrupt handler.
CPU0
----
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount odd
// e.g. timer interrupt handler runs at this moment
some_timer_func() {
kmalloc(GFP_ATOMIC) {
__alloc_pages_slowpath() {
read_seqbegin(&zonelist_update_seq) {
// spins forever because zonelist_update_seq.seqcount is odd
}
}
}
}
// e.g. timer interrupt handler finishes
write_sequnlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount even
}
This deadlock scenario can be easily eliminated by not calling
read_seqbegin(&zonelist_update_seq) from !__GFP_DIRECT_RECLAIM allocation
requests, for retry is applicable to only __GFP_DIRECT_RECLAIM allocation
requests. But Michal Hocko does not know whether we should go with this
approach.
Another deadlock scenario which syzbot is reporting is a race between
kmalloc(GFP_ATOMIC) from tty_insert_flip_string_and_push_buffer() with
port->lock held and printk() from __build_all_zonelists() with
zonelist_update_seq held.
CPU0 CPU1
---- ----
pty_write() {
tty_insert_flip_string_and_push_buffer() {
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq);
build_zonelists() {
printk() {
vprintk() {
vprintk_default() {
vprintk_emit() {
console_unlock() {
console_flush_all() {
console_emit_next_record() {
con->write() = serial8250_console_write() {
spin_lock_irqsave(&port->lock, flags);
tty_insert_flip_string() {
tty_insert_flip_string_fixed_flag() {
__tty_buffer_request_room() {
tty_buffer_alloc() {
kmalloc(GFP_ATOMIC | __GFP_NOWARN) {
__alloc_pages_slowpath() {
zonelist_iter_begin() {
read_seqbegin(&zonelist_update_seq); // spins forever because zonelist_update_seq.seqcount is odd
spin_lock_irqsave(&port->lock, flags); // spins forever because port->lock is held
}
}
}
}
}
}
}
}
spin_unlock_irqrestore(&port->lock, flags);
// message is printed to console
spin_unlock_irqrestore(&port->lock, flags);
}
}
}
}
}
}
}
}
}
write_sequnlock(&zonelist_update_seq);
}
}
}
This deadlock scenario can be eliminated by
preventing interrupt context from calling kmalloc(GFP_ATOMIC)
and
preventing printk() from calling console_flush_all()
while zonelist_update_seq.seqcount is odd.
Since Petr Mladek thinks that __build_all_zonelists() can become a
candidate for deferring printk() [2], let's address this problem by
disabling local interrupts in order to avoid kmalloc(GFP_ATOMIC)
and
disabling synchronous printk() in order to avoid console_flush_all()
.
As a side effect of minimizing duration of zonelist_update_seq.seqcount
being odd by disabling synchronous printk(), latency at
read_seqbegin(&zonelist_update_seq) for both !__GFP_DIRECT_RECLAIM and
__GFP_DIRECT_RECLAIM allocation requests will be reduced. Although, from
lockdep perspective, not calling read_seqbegin(&zonelist_update_seq) (i.e.
do not record unnecessary locking dependency) from interrupt context is
still preferable, even if we don't allow calling kmalloc(GFP_ATOMIC)
inside
write_seqlock(&zonelist_update_seq)/write_sequnlock(&zonelist_update_seq)
section...
Link: https://lkml.kernel.org/r/8796b95c-3da3-5885-fddd-6ef55f30e4d3@I-love.SAKURA.ne.jp
Fixes: 3d36424b3b ("mm/page_alloc: fix race condition between build_all_zonelists and page allocation")
Link: https://lkml.kernel.org/r/ZCrs+1cDqPWTDFNM@alley [2]
Reported-by: syzbot <syzbot+223c7461c58c58a4cb10@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=223c7461c58c58a4cb10 [1]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Patrick Daly <quic_pdaly@quicinc.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mem_init_print_info() is only called from mm_core_init().
Move it close to the caller and make it static.
Link: https://lkml.kernel.org/r/20230321170513.2401534-12-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
init_mem_debugging_and_hardening() is only called from mm_core_init().
Move it close to the caller, make it static and rename it to
mem_debugging_and_hardening_init() for consistency with surrounding
convention.
Link: https://lkml.kernel.org/r/20230321170513.2401534-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The page_alloc_init() name is really misleading because all this function
does is sets up CPU hotplug callbacks for the page allocator.
Rename it to page_alloc_init_cpuhp() so that name will reflect what the
function does.
Link: https://lkml.kernel.org/r/20230321170513.2401534-6-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The hashdist variable must be initialized before the first call to
alloc_large_system_hash() and free_area_init() looks like a better place
for it than page_alloc_init().
Move hashdist handling to mm/mm_init.c
Link: https://lkml.kernel.org/r/20230321170513.2401534-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The bulk of memory management initialization code is spread all over
mm/page_alloc.c and makes navigating through page allocator functionality
difficult.
Move most of the functions marked __init and __meminit to mm/mm_init.c to
make it better localized and allow some more spare room before
mm/page_alloc.c reaches 10k lines.
No functional changes.
Link: https://lkml.kernel.org/r/20230321170513.2401534-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of duplicating long static_branch_enabled(&check_pages_enabled)
wrap it in a helper function is_check_pages_enabled()
Link: https://lkml.kernel.org/r/20230321170513.2401534-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The get_page_from_free_area() helper is only used in mm/page_alloc.c so
move it there to reduce noise in include/linux/mmzone.h
Link: https://lkml.kernel.org/r/20230319114214.2133332-1-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Code inspection reveals that PG_skip_kasan_poison is redundant with
kasantag, because the former is intended to be set iff the latter is the
match-all tag. It can also be observed that it's basically pointless to
poison pages which have kasantag=0, because any pages with this tag would
have been pointed to by pointers with match-all tags, so poisoning the
pages would have little to no effect in terms of bug detection.
Therefore, change the condition in should_skip_kasan_poison() to check
kasantag instead, and remove PG_skip_kasan_poison and associated flags.
Link: https://lkml.kernel.org/r/20230310042914.3805818-3-pcc@google.com
Link: https://linux-review.googlesource.com/id/I57f825f2eaeaf7e8389d6cf4597c8a5821359838
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Historically, we have performed sanity checks on all struct pages being
allocated or freed, making sure they have no unexpected page flags or
certain field values. This can detect insufficient cleanup and some cases
of use-after-free, although on its own it can't always identify the
culprit. The result is a warning and the "bad page" being leaked.
The checks do need some cpu cycles, so in 4.7 with commits 479f854a20
("mm, page_alloc: defer debugging checks of pages allocated from the PCP")
and 4db7548ccb ("mm, page_alloc: defer debugging checks of freed pages
until a PCP drain") they were no longer performed in the hot paths when
allocating and freeing from pcplists, but only when pcplists are bypassed,
refilled or drained. For debugging purposes, with CONFIG_DEBUG_VM enabled
the checks were instead still done in the hot paths and not when refilling
or draining pcplists.
With 4462b32c92 ("mm, page_alloc: more extensive free page checking with
debug_pagealloc"), enabling debug_pagealloc also moved the sanity checks
back to hot pahs. When both debug_pagealloc and CONFIG_DEBUG_VM are
enabled, the checks are done both in hotpaths and pcplist refill/drain.
Even though the non-debug default today might seem to be a sensible
tradeoff between overhead and ability to detect bad pages, on closer look
it's arguably not. As most allocations go through the pcplists, catching
any bad pages when refilling or draining pcplists has only a small chance,
insufficient for debugging or serious hardening purposes. On the other
hand the cost of the checks is concentrated in the already expensive
drain/refill batching operations, and those are done under the often
contended zone lock. That was recently identified as an issue for page
allocation and the zone lock contention reduced by moving the checks
outside of the locked section with a patch "mm: reduce lock contention of
pcp buffer refill", but the cost of the checks is still visible compared
to their removal [1]. In the pcplist draining path free_pcppages_bulk()
the checks are still done under zone->lock.
Thus, remove the checks from pcplist refill and drain paths completely.
Introduce a static key check_pages_enabled to control checks during page
allocation a freeing (whether pcplist is used or bypassed). The static
key is enabled if either is true:
- kernel is built with CONFIG_DEBUG_VM=y (debugging)
- debug_pagealloc or page poisoning is boot-time enabled (debugging)
- init_on_alloc or init_on_free is boot-time enabled (hardening)
The resulting user visible changes:
- no checks when draining/refilling pcplists - less overhead, with
likely no practical reduction of ability to catch bad pages
- no checks when bypassing pcplists in default config (no
debugging/hardening) - less overhead etc. as above
- on typical hardened kernels [2], checks are now performed on each page
allocation/free (previously only when bypassing/draining/refilling
pcplists) - the init_on_alloc/init_on_free enabled should be sufficient
indication for preferring more costly alloc/free operations for
hardening purposes and we shouldn't need to introduce another toggle
- code (various wrappers) removal and simplification
[1] https://lore.kernel.org/all/68ba44d8-6899-c018-dcb3-36f3a96e6bea@sra.uni-hannover.de/
[2] https://lore.kernel.org/all/63ebc499.a70a0220.9ac51.29ea@mx.google.com/
[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: make check_pages_enabled static]
Link: https://lkml.kernel.org/r/20230216095131.17336-1-vbabka@suse.cz
Reported-by: Alexander Halbuer <halbuer@sra.uni-hannover.de>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
rmqueue_bulk() batches the allocation of multiple elements to refill the
per-CPU buffers into a single hold of the zone lock. Each element is
allocated and checked using check_pcp_refill(). The check touches every
related struct page which is especially expensive for higher order
allocations (huge pages).
This patch reduces the time holding the lock by moving the check out of
the critical section similar to rmqueue_buddy() which allocates a single
element.
Measurements of parallel allocation-heavy workloads show a reduction of
the average huge page allocation latency of 50 percent for two cores and
nearly 90 percent for 24 cores.
Link: https://lkml.kernel.org/r/20230201162549.68384-1-halbuer@sra.uni-hannover.de
Signed-off-by: Alexander Halbuer <halbuer@sra.uni-hannover.de>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 002f290627 ("cpuset: use static key better and convert to new API")
has used __cpuset_node_allowed() instead of cpuset_node_allowed() to check
whether we can allocate on a memory node. Now this function isn't used by
anyone, so we can do the follow things to clean up it.
1. remove unused codes
2. rename __cpuset_node_allowed() to cpuset_node_allowed()
3. update comments in mm/page_alloc.c
Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This reverts commit 487a32ec24.
should_skip_kasan_poison() reads the PG_skip_kasan_poison flag from
page->flags. However, this line of code in free_pages_prepare():
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
clears most of page->flags, including PG_skip_kasan_poison, before calling
should_skip_kasan_poison(), which meant that it would never return true as
a result of the page flag being set. Therefore, fix the code to call
should_skip_kasan_poison() before clearing the flags, as we were doing
before the reverted patch.
This fixes a measurable performance regression introduced in the reverted
commit, where munmap() takes longer than intended if HW tags KASAN is
supported and enabled at runtime. Without this patch, we see a
single-digit percentage performance regression in a particular
mmap()-heavy benchmark when enabling HW tags KASAN, and with the patch,
there is no statistically significant performance impact when enabling HW
tags KASAN.
Link: https://lkml.kernel.org/r/20230310042914.3805818-2-pcc@google.com
Fixes: 487a32ec24 ("kasan: drop skip_kasan_poison variable in free_pages_prepare")
Link: https://linux-review.googlesource.com/id/Ic4f13affeebd20548758438bb9ed9ca40e312b79
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org> [6.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter". These filters provide users
with finer-grained control over DAMOS's actions. SeongJae has also done
some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series "mm:
support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with his
series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings. The previous BPF-based approach had
shortcomings. See "mm: In-kernel support for memory-deny-write-execute
(MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a per-node
basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage during
compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in ths
series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's series
"mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
"fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest of
the kernel in the series "Simplify the external interface for GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the series
"mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X
bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()")
which does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter".
These filters provide users with finer-grained control over DAMOS's
actions. SeongJae has also done some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series
"mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
swap PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with
his series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings.
The previous BPF-based approach had shortcomings. See "mm: In-kernel
support for memory-deny-write-execute (MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a
per-node basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage
during compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in
ths series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier
functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's
series "mm, arch: add generic implementation of pfn_valid() for
FLATMEM" and "fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest
of the kernel in the series "Simplify the external interface for
GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the
series "mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
include/linux/migrate.h: remove unneeded externs
mm/memory_hotplug: cleanup return value handing in do_migrate_range()
mm/uffd: fix comment in handling pte markers
mm: change to return bool for isolate_movable_page()
mm: hugetlb: change to return bool for isolate_hugetlb()
mm: change to return bool for isolate_lru_page()
mm: change to return bool for folio_isolate_lru()
objtool: add UACCESS exceptions for __tsan_volatile_read/write
kmsan: disable ftrace in kmsan core code
kasan: mark addr_has_metadata __always_inline
mm: memcontrol: rename memcg_kmem_enabled()
sh: initialize max_mapnr
m68k/nommu: add missing definition of ARCH_PFN_OFFSET
mm: percpu: fix incorrect size in pcpu_obj_full_size()
maple_tree: reduce stack usage with gcc-9 and earlier
mm: page_alloc: call panic() when memoryless node allocation fails
mm: multi-gen LRU: avoid futile retries
migrate_pages: move THP/hugetlb migration support check to simplify code
migrate_pages: batch flushing TLB
migrate_pages: share more code between _unmap and _move
...
Currently there are two kmem-related helper functions with a confusing
semantics: memcg_kmem_enabled() and mem_cgroup_kmem_disabled().
The problem is that an obvious expectation
memcg_kmem_enabled() == !mem_cgroup_kmem_disabled(),
can be false.
mem_cgroup_kmem_disabled() is similar to mem_cgroup_disabled(): it returns
true only if CONFIG_MEMCG_KMEM is not set or the kmem accounting is
disabled using a boot time kernel option "cgroup.memory=nokmem". It never
changes the value dynamically.
memcg_kmem_enabled() is different: it always returns false until the first
non-root memory cgroup will get online (assuming the kernel memory
accounting is enabled). It's goal is to improve the performance on
systems without the cgroupfs mounted/memory controller enabled or on the
systems with only the root memory cgroup.
To make things more obvious and avoid potential bugs, let's rename
memcg_kmem_enabled() to memcg_kmem_online().
Link: https://lkml.kernel.org/r/20230213192922.1146370-1-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In free_area_init(), we will continue to run after allocation of
memoryless node pgdat fails. However, in the subsequent process (such as
when initializing zonelist), the case that NODE_DATA(nid) is NULL is not
handled, which will cause panic. Instead of this, it's better to call
panic() directly when the memory allocation fails during system boot.
Link: https://lkml.kernel.org/r/20230212111027.95520-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When we upgraded our kernel, we started seeing some page corruption like
the following consistently:
BUG: Bad page state in process ganesha.nfsd pfn:1304ca
page:0000000022261c55 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x1304ca
flags: 0x17ffffc0000000()
raw: 0017ffffc0000000 ffff8a513ffd4c98 ffffeee24b35ec08 0000000000000000
raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
page dumped because: nonzero mapcount
CPU: 0 PID: 15567 Comm: ganesha.nfsd Kdump: loaded Tainted: P B O 5.10.158-1.nutanix.20221209.el7.x86_64 #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
Call Trace:
dump_stack+0x74/0x96
bad_page.cold+0x63/0x94
check_new_page_bad+0x6d/0x80
rmqueue+0x46e/0x970
get_page_from_freelist+0xcb/0x3f0
? _cond_resched+0x19/0x40
__alloc_pages_nodemask+0x164/0x300
alloc_pages_current+0x87/0xf0
skb_page_frag_refill+0x84/0x110
...
Sometimes, it would also show up as corruption in the free list pointer
and cause crashes.
After bisecting the issue, we found the issue started from commit
e320d3012d ("mm/page_alloc.c: fix freeing non-compound pages"):
if (put_page_testzero(page))
free_the_page(page, order);
else if (!PageHead(page))
while (order-- > 0)
free_the_page(page + (1 << order), order);
So the problem is the check PageHead is racy because at this point we
already dropped our reference to the page. So even if we came in with
compound page, the page can already be freed and PageHead can return
false and we will end up freeing all the tail pages causing double free.
Fixes: e320d3012d ("mm/page_alloc.c: fix freeing non-compound pages")
Link: https://lore.kernel.org/lkml/BYAPR02MB448855960A9656EEA81141FC94D99@BYAPR02MB4488.namprd02.prod.outlook.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The commit 1dd214b8f2 ("mm: page_alloc: avoid merging non-fallbackable
pageblocks with others") has removed MIGRATE_CMA and MIGRATE_ISOLATE from
fallbacks list. so there is no need to add an element at the end of every
type.
Reduce fallbacks to (MIGRATE_PCPTYPES - 1).
Link: https://lkml.kernel.org/r/20230203100132.1627787-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The implementation of page_alloc poisoning sampling assumed that
tag_clear_highpage resets page tags for __GFP_ZEROTAGS allocations.
However, this is no longer the case since commit 70c248aca9 ("mm: kasan:
Skip unpoisoning of user pages").
This leads to kernel crashes when MTE-enabled userspace mappings are used
with Hardware Tag-Based KASAN enabled.
Reset page tags for __GFP_ZEROTAGS allocations in post_alloc_hook().
Also clarify and fix related comments.
[andreyknvl@google.com: update comment]
Link: https://lkml.kernel.org/r/5dbd866714b4839069e2d8469ac45b60953db290.1674592780.git.andreyknvl@google.com
Link: https://lkml.kernel.org/r/24ea20c1b19c2b4b56cf9f5b354915f8dbccfc77.1674592496.git.andreyknvl@google.com
Fixes: 44383cef54 ("kasan: allow sampling page_alloc allocations for HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Peter Collingbourne <pcc@google.com>
Tested-by: Peter Collingbourne <pcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of directly accessing static deferred_pages, replace such
instances with the helper deferred_pages_enabled(). No functional change
is intended.
Link: https://lkml.kernel.org/r/20230105082506.241529-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
page_ext must be initialized after all struct pages are initialized.
Therefore, page_ext is initialized after page_alloc_init_late(), and can
optionally be initialized earlier via early_page_ext kernel parameter
which as a side effect also disables deferred struct pages.
Allow to automatically init page_ext early when there are no deferred
struct pages in order to be able to use page_ext during kernel boot and
track for example page allocations early.
[pasha.tatashin@soleen.com: fix build with CONFIG_PAGE_EXTENSION=n]
Link: https://lkml.kernel.org/r/20230118155251.2522985-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20230117204617.1553748-1-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Charan Teja Kalla <quic_charante@quicinc.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__GFP_ATOMIC serves little purpose. Its main effect is to set
ALLOC_HARDER which adds a few little boosts to increase the chance of an
allocation succeeding, one of which is to lower the water-mark at which it
will succeed.
It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also
adjusts this watermark. It is probable that other users of __GFP_HIGH
should benefit from the other little bonuses that __GFP_ATOMIC gets.
__GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM.
There is little point to this. We already get a might_sleep() warning if
__GFP_DIRECT_RECLAIM is set.
__GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is
probable that testing ALLOC_HARDER is a better fit here.
__GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might
sleep. This should test __GFP_DIRECT_RECLAIM instead.
This patch:
- removes __GFP_ATOMIC
- allows __GFP_HIGH allocations to ignore watermark boosting as well
as GFP_ATOMIC requests.
- makes other adjustments as suggested by the above.
The net result is not change to GFP_ATOMIC allocations. Other
allocations that use __GFP_HIGH will benefit from a few different extra
privileges. This affects:
xen, dm, md, ntfs3
the vermillion frame buffer
hibernation
ksm
swap
all of which likely produce more benefit than cost if these selected
allocation are more likely to succeed quickly.
[mgorman: Minor adjustments to rework on top of a series]
Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name
Link: https://lkml.kernel.org/r/20230113111217.14134-7-mgorman@techsingularity.net
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
GFP_ATOMIC allocations get flagged ALLOC_HARDER which is a vague
description. In preparation for the removal of GFP_ATOMIC redefine
__GFP_ATOMIC to simply mean non-blocking and renaming ALLOC_HARDER to
ALLOC_NON_BLOCK accordingly. __GFP_HIGH is required for access to
reserves but non-blocking is granted more access. For example, GFP_NOWAIT
is non-blocking but has no special access to reserves. A __GFP_NOFAIL
blocking allocation is granted access similar to __GFP_HIGH if the only
alternative is an OOM kill.
Link: https://lkml.kernel.org/r/20230113111217.14134-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
As there are more ALLOC_ flags that affect reserves, define what flags
affect reserves and clarify the effect of each flag.
Link: https://lkml.kernel.org/r/20230113111217.14134-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan