The recommended ways for getting DAMON monitoring results are using
tried_regions sysfs directory for partial snapshot of the results, and
DAMON tracepoint for full record of the results. However, the
tried_regions sysfs directory usage has not sufficiently updated on some
sections of the DAMON usage document. Update those.
Link: https://lkml.kernel.org/r/20230616191742.87531-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Explanation of DAMOS quotas and watermarks are not clearly explaining the
meaning and expectation of each file. Add more clarification for those.
Link: https://lkml.kernel.org/r/20230616191742.87531-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The background and concept of DAMOS is redundantly documented, in the
design document and the usage document. Replace the duplicated ones in
usage document with links to the design document.
Link: https://lkml.kernel.org/r/20230616191742.87531-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Brief explanation of DAMON user space tool and sysfs interface are
unnecessarily and repeatedly mentioning the list of address spaces that
DAMON is supporting. Remove those.
Link: https://lkml.kernel.org/r/20230616191742.87531-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix typos including a unnecessary comma and incomplete ':ref:' keywords.
Link: https://lkml.kernel.org/r/20230616191742.87531-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON user-space tool, damo, has deprecated[1] its old DAMOS schemes
specification format. However, an example of DAMON documentation is still
using it. Update the example to use one of the alternative options.
[1] https://github.com/awslabs/damo/commit/e9950ae68f6c
Link: https://lkml.kernel.org/r/20230616191742.87531-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Docs/{mm,admin-guide}damon: update design and usage docs".
Update DAMON design and usage documents for outdated and unnecessarily
duplicated parts.
This patch (of 7):
The 'age' of each region in DAMON monitoring results is an important
concept for both monitoring part and DAMOS. And DAMOS section of the
design document is mentioning it. However, the age itself is not
explained in the document. Add a section for that.
Link: https://lkml.kernel.org/r/20230616191742.87531-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230616191742.87531-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mm_struct mm_count field is frequently updated by mmgrab/mmdrop
performed by context switch. This causes false-sharing for surrounding
mm_struct fields which are read-mostly.
This has been observed on a 2sockets/112core/224cpu Intel Sapphire Rapids
server running hackbench, and by the kernel test robot will-it-scale
testcase.
Move the mm_count field into its own cache line to prevent false-sharing
with other mm_struct fields.
Move mm_count to the first field of mm_struct to minimize the amount of
padding required: rather than adding padding before and after the mm_count
field, padding is only added after mm_count.
Note that I noticed this odd comment in mm_struct:
commit 2e3025434a ("mm: relocate 'write_protect_seq' in struct mm_struct")
/*
* With some kernel config, the current mmap_lock's offset
* inside 'mm_struct' is at 0x120, which is very optimal, as
* its two hot fields 'count' and 'owner' sit in 2 different
* cachelines, and when mmap_lock is highly contended, both
* of the 2 fields will be accessed frequently, current layout
* will help to reduce cache bouncing.
*
* So please be careful with adding new fields before
* mmap_lock, which can easily push the 2 fields into one
* cacheline.
*/
struct rw_semaphore mmap_lock;
This comment is rather odd for a few reasons:
- It requires addition/removal of mm_struct fields to carefully consider
field alignment of _other_ fields,
- It expresses the wish to keep an "optimal" alignment for a specific
kernel config.
I suspect that the author of this comment may want to revisit this topic
and perhaps introduce a split-struct approach for struct rw_semaphore,
if the need is to place various fields of this structure in different
cache lines.
Link: https://lkml.kernel.org/r/20230515143536.114960-1-mathieu.desnoyers@efficios.com
Fixes: 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
Fixes: af7f588d8f ("sched: Introduce per-memory-map concurrency ID")
Link: https://lore.kernel.org/lkml/7a0c1db1-103d-d518-ed96-1584a28fbf32@efficios.com
Reported-by: kernel test robot <yujie.liu@intel.com>
Link: https://lore.kernel.org/oe-lkp/202305151017.27581d75-yujie.liu@intel.com
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Olivier Dion <odion@efficios.com>
Cc: <michael.christie@oracle.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
No user checks the return value of mem_cgroup_scan_tasks(). Make the
return value void.
Link: https://lkml.kernel.org/r/20230616063030.977586-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 5ff6e2fff8 ("mm/damon/core: fix divide error in
damon_nr_accesses_to_accesses_bp()") fixed a bug by adding arguments
validation in damon_set_attrs(). Add a unit test for the added validation
to ensure the bug cannot occur again.
Link: https://lkml.kernel.org/r/20230615183323.87561-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
folio_is_longterm_pinnable() already exists as a wrapper function. Now
that the whole implementation of is_longterm_pinnable_page() can be
implemented using folios, folio_is_longterm_pinnable() can be made its own
standalone function - and we can remove is_longterm_pinnable_page().
Link: https://lkml.kernel.org/r/20230614021312.34085-6-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
try_get_folio() takes in a page, then chooses to do some folio operations
based on the flags (either FOLL_GET or FOLL_PIN). We can rewrite this
function to be more purpose oriented.
After calling try_get_folio(), if neither FOLL_GET nor FOLL_PIN are set,
warn and fail. If FOLL_GET is set we can return the result. If FOLL_GET
is not set then FOLL_PIN is set, so we pin the folio.
This change assists with folio conversions, and makes the function more
readable.
Link: https://lkml.kernel.org/r/20230614021312.34085-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
verify_dma_pinned() checks that pages are dma-pinned. We can convert this
to use folios.
Link: https://lkml.kernel.org/r/20230614021312.34085-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce folio_migratetype() as a folio equivalent for
get_pageblock_migratetype(). This function intends to return the
migratetype the folio is located in, hence the name choice.
Link: https://lkml.kernel.org/r/20230614021312.34085-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Replace is_longterm_pinnable_page()", v2.
This patchset introduces some more helper functions for the folio
conversions, and converts all callers of is_longterm_pinnable_page() to
use folios.
This patch (of 5):
Introduce folio_is_zone_movable() to act as a folio equivalent for
is_zone_movable_page(). This is to assist in later folio conversions.
Link: https://lkml.kernel.org/r/20230614021312.34085-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20230614021312.34085-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
KASAN's boot time kernel parameter 'kasan.fault=' currently supports
'report' and 'panic', which results in either only reporting bugs or also
panicking on reports.
However, some users may wish to have more control over when KASAN reports
result in a kernel panic: in particular, KASAN reported invalid _writes_
are of special interest, because they have greater potential to corrupt
random kernel memory or be more easily exploited.
To panic on invalid writes only, introduce 'kasan.fault=panic_on_write',
which allows users to choose to continue running on invalid reads, but
panic only on invalid writes.
Link: https://lkml.kernel.org/r/20230614095158.1133673-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Recompression threshold should be below huge-size-class watermark. Any
object larger than huge-size-class is a "huge object" and occupies a
whole physical page on the zsmalloc side, in other words it's
incompressible, as far as zsmalloc is concerned.
Link: https://lkml.kernel.org/r/20230614141338.3480029-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Suggested-by: Brian Geffon <bgeffon@google.com>
Acked-by: Brian Geffon <bgeffon@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When an entry started writeback, it used to be invalidated with ref count
logic alone, meaning that it would stay on the tree until all references
were put. The problem with this behavior is that as soon as the writeback
started, the ownership of the data held by the entry is passed to the
swapcache and should not be left in zswap too. Currently there are no
known issues because of this, but this change explicitly invalidates an
entry that started writeback to reduce opportunities for future bugs.
This patch is a follow up on the series titled "mm: zswap: move writeback
LRU from zpool to zswap" + commit f090b7949768("mm: zswap: support
exclusive loads").
Link: https://lkml.kernel.org/r/20230614143122.74471-1-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit c7c3dec1c9 ("mm: rmap: remove lock_page_memcg()"),
no more user, kill lock_page_memcg() and unlock_page_memcg().
Link: https://lkml.kernel.org/r/20230614143612.62575-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
cma: display pfn as well as pfn_to_page(pfn)
page_owner: display pfn in hex rather than decimal
Link: https://lkml.kernel.org/r/20230613092533.15449-1-quic_yingangl@quicinc.com
Signed-off-by: Kassey Li <quic_yingangl@quicinc.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Support large folios in block_truncate_page() and avoid three hidden calls
to compound_head().
[willy@infradead.org: fix check of filemap_grab_folio() return value]
Link: https://lkml.kernel.org/r/ZItZOt+XxV12HtzL@casper.infradead.org
Link: https://lkml.kernel.org/r/20230612210141.730128-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Saves a call to compound_head() and may be needed to support block size >
PAGE_SIZE.
Link: https://lkml.kernel.org/r/20230612210141.730128-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Its one caller already has a folio, so switch it to use the folio API.
Removes a hidden call to compound_head().
Link: https://lkml.kernel.org/r/20230612210141.730128-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the folio API and pass the folio from both callers. Saves a hidden
call to compound_head().
Link: https://lkml.kernel.org/r/20230612210141.730128-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Get a folio from the page cache instead of a page, then use the folio API
throughout. Removes a few calls to compound_head() and may be needed to
support block size > PAGE_SIZE.
Link: https://lkml.kernel.org/r/20230612210141.730128-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Most of the callers already have a folio; convert reiserfs_write_end() to
have a folio. Removes a couple of hidden calls to compound_head().
Link: https://lkml.kernel.org/r/20230612210141.730128-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This removes a hidden call to compound_head() inside
__block_commit_write() and moves it to those callers which are still page
based. Also make block_write_end() safe for large folios.
Link: https://lkml.kernel.org/r/20230612210141.730128-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If any page in a folio is dirtied, dirty the entire folio. Removes a
number of hidden calls to compound_head() and references to page->mapping
and page->index. Fixes a pre-existing bug where we could mark a folio as
dirty if the file is truncated to a multiple of the page size just as we
take the page fault. I don't believe this bug has any bad effect, it's
just inefficient.
Link: https://lkml.kernel.org/r/20230612210141.730128-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Keep the interface as struct page, but work entirely on the folio
internally. Removes several PAGE_SIZE assumptions and removes some
references to page->index and page->mapping.
Link: https://lkml.kernel.org/r/20230612210141.730128-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We may someday support folios larger than 4GB, so use a size_t for the
byte count within a folio to prevent unpleasant truncations.
Link: https://lkml.kernel.org/r/20230612210141.730128-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove nine hidden calls to compound_head() by using a folio instead of a
page.
Link: https://lkml.kernel.org/r/20230612210141.730128-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add support for large folios and remove some accesses to page->mapping and
page->index.
Link: https://lkml.kernel.org/r/20230612210141.730128-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove a couple of folio->page conversions in the callers, and two calls
to compound_head() in the function itself. Rename it from
__gfs2_jdata_writepage() to __gfs2_jdata_write_folio().
Link: https://lkml.kernel.org/r/20230612210141.730128-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "gfs2/buffer folio changes for 6.5", v3.
This kind of started off as a gfs2 patch series, then became entwined with
buffer heads once I realised that gfs2 was the only remaining caller of
__block_write_full_page(). For those not in the gfs2 world, the big point
of this series is that block_write_full_page() should now handle large
folios correctly.
This patch (of 14):
Replace a few implicit calls to compound_head() with one explicit one.
Link: https://lkml.kernel.org/r/20230612210141.730128-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20230612210141.730128-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These are equivalent, but DEFINE_READ_MOSTLY_HASHTABLE exists to define
a hashtable in the .data..read_mostly section.
Link: https://lkml.kernel.org/r/20230609-khugepage-v1-1-dad4e8382298@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When running UnixBench/Execl throughput case, false sharing is observed
due to frequent read on base_addr and write on free_bytes, chunk_md.
UnixBench/Execl represents a class of workload where bash scripts are
spawned frequently to do some short jobs. It will do system call on execl
frequently, and execl will call mm_init to initialize mm_struct of the
process. mm_init will call __percpu_counter_init for percpu_counters
initialization. Then pcpu_alloc is called to read the base_addr of
pcpu_chunk for memory allocation. Inside pcpu_alloc, it will call
pcpu_alloc_area to allocate memory from a specified chunk. This function
will update "free_bytes" and "chunk_md" to record the rest free bytes and
other meta data for this chunk. Correspondingly, pcpu_free_area will also
update these 2 members when free memory.
Call trace from perf is as below:
+ 57.15% 0.01% execl [kernel.kallsyms] [k] __percpu_counter_init
+ 57.13% 0.91% execl [kernel.kallsyms] [k] pcpu_alloc
- 55.27% 54.51% execl [kernel.kallsyms] [k] osq_lock
- 53.54% 0x654278696e552f34
main
__execve
entry_SYSCALL_64_after_hwframe
do_syscall_64
__x64_sys_execve
do_execveat_common.isra.47
alloc_bprm
mm_init
__percpu_counter_init
pcpu_alloc
- __mutex_lock.isra.17
In current pcpu_chunk layout, `base_addr' is in the same cache line with
`free_bytes' and `chunk_md', and `base_addr' is at the last 8 bytes. This
patch moves `bound_map' up to `base_addr', to let `base_addr' locate in a
new cacheline.
With this change, on Intel Sapphire Rapids 112C/224T platform, based on
v6.4-rc4, the 160 parallel score improves by 24%.
The pcpu_chunk struct is a backing data structure per chunk, so the
additional memory should not be dramatic. A chunk covers ballpark
between 64kb and 512kb memory depending on some config and boot time
stuff, so I believe the additional memory used here is nominal at best.
Working the #s on my desktop:
Percpu: 58624 kB
28 cores -> ~2.1MB of percpu memory.
At say ~128KB per chunk -> 33 chunks, generously 40 chunks.
Adding alignment might bump the chunk size ~64 bytes, so in total ~2KB
of overhead?
I believe we can do a little better to avoid eating that full padding,
so likely less than that.
[dennis@kernel.org: changelog details]
Link: https://lkml.kernel.org/r/20230610030730.110074-1-yu.ma@intel.com
Signed-off-by: Yu Ma <yu.ma@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
establish_demotion_targets() is defined while CONFIG_MIGRATION is
enabled. There's no need to check it again.
Link: https://lkml.kernel.org/r/20230610034114.981861-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add __meminit to kcompactd_run() and kcompactd_stop() to ensure they're
default to __init when memory hotplug is not enabled.
Link: https://lkml.kernel.org/r/20230610034615.997813-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This inline function is unused, remove it.
Link: https://lkml.kernel.org/r/20230610102858.31488-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Android reported a performance regression in the userfaultfd unmap path.
A closer inspection on the userfaultfd_unmap_prep() change showed that a
second tree walk would be necessary in the reworked code.
Fix the regression by passing each VMA that will be unmapped through to
the userfaultfd_unmap_prep() function as they are added to the unmap list,
instead of re-walking the tree for the VMA.
Link: https://lkml.kernel.org/r/20230601015402.2819343-1-Liam.Howlett@oracle.com
Fixes: 69dbe6daf1 ("userfaultfd: use maple tree iterator to iterate VMAs")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The patch ("mm/folio: Avoid special handling for order value 0 in
folio_set_order") [1] removed the need for special handling of order = 0
in folio_set_order. Now, folio_set_order and set_compound_order becomes
similar function. This patch removes the set_compound_order and uses
folio_set_order instead.
[1] https://lore.kernel.org/all/20230609183032.13E08C433D2@smtp.kernel.org/
Link: https://lkml.kernel.org/r/20230612093514.689846-1-tsahu@linux.ibm.com
Signed-off-by: Tarun Sahu <tsahu@linux.ibm.com>
Reviewed-by Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously, zswap_header served the purpose of storing the swpentry within
zpool pages. This allowed zpool implementations to pass relevant
information to the writeback function. However, with the current
implementation, writeback is directly handled within zswap. Consequently,
there is no longer a necessity for zswap_header, as the swp_entry_t can be
stored directly in zswap_entry.
Link: https://lkml.kernel.org/r/20230612093815.133504-8-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Tested-by: Yosry Ahmed <yosryahmed@google.com>
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
zswap_writeback_entry() used to be a callback for the backends, which
don't know about struct zswap_entry.
Now that the only user is the generic zswap LRU reclaimer, it can be
simplified: pass the pinned zswap_entry directly, and consolidate the
refcount management in the shrink function.
Link: https://lkml.kernel.org/r/20230612093815.133504-7-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Tested-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that all three zswap backends have removed their shrink code, it is
no longer necessary for the zpool interface to include shrink/writeback
endpoints.
Link: https://lkml.kernel.org/r/20230612093815.133504-6-cerasuolodomenico@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrew Morton