linux-stable/mm
Mel Gorman 5d83306213 mm: numa: do not dereference pmd outside of the lock during NUMA hinting fault
Automatic NUMA balancing depends on being able to protect PTEs to trap a
fault and gather reference locality information.  Very broadly speaking
it would mark PTEs as not present and use another bit to distinguish
between NUMA hinting faults and other types of faults.  It was
universally loved by everybody and caused no problems whatsoever.  That
last sentence might be a lie.

This series is very heavily based on patches from Linus and Aneesh to
replace the existing PTE/PMD NUMA helper functions with normal change
protections.  I did alter and add parts of it but I consider them
relatively minor contributions.  At their suggestion, acked-bys are in
there but I've no problem converting them to Signed-off-by if requested.

AFAIK, this has received no testing on ppc64 and I'm depending on Aneesh
for that.  I tested trinity under kvm-tool and passed and ran a few
other basic tests.  At the time of writing, only the short-lived tests
have completed but testing of V2 indicated that long-term testing had no
surprises.  In most cases I'm leaving out detail as it's not that
interesting.

specjbb single JVM: There was negligible performance difference in the
	benchmark itself for short runs. However, system activity is
	higher and interrupts are much higher over time -- possibly TLB
	flushes. Migrations are also higher. Overall, this is more overhead
	but considering the problems faced with the old approach I think
	we just have to suck it up and find another way of reducing the
	overhead.

specjbb multi JVM: Negligible performance difference to the actual benchmark
	but like the single JVM case, the system overhead is noticeably
	higher.  Again, interrupts are a major factor.

autonumabench: This was all over the place and about all that can be
	reasonably concluded is that it's different but not necessarily
	better or worse.

autonumabench
                                     3.18.0-rc5            3.18.0-rc5
                                 mmotm-20141119         protnone-v3r3
User    NUMA01               32380.24 (  0.00%)    21642.92 ( 33.16%)
User    NUMA01_THEADLOCAL    22481.02 (  0.00%)    22283.22 (  0.88%)
User    NUMA02                3137.00 (  0.00%)     3116.54 (  0.65%)
User    NUMA02_SMT            1614.03 (  0.00%)     1543.53 (  4.37%)
System  NUMA01                 322.97 (  0.00%)     1465.89 (-353.88%)
System  NUMA01_THEADLOCAL       91.87 (  0.00%)       49.32 ( 46.32%)
System  NUMA02                  37.83 (  0.00%)       14.61 ( 61.38%)
System  NUMA02_SMT               7.36 (  0.00%)        7.45 ( -1.22%)
Elapsed NUMA01                 716.63 (  0.00%)      599.29 ( 16.37%)
Elapsed NUMA01_THEADLOCAL      553.98 (  0.00%)      539.94 (  2.53%)
Elapsed NUMA02                  83.85 (  0.00%)       83.04 (  0.97%)
Elapsed NUMA02_SMT              86.57 (  0.00%)       79.15 (  8.57%)
CPU     NUMA01                4563.00 (  0.00%)     3855.00 ( 15.52%)
CPU     NUMA01_THEADLOCAL     4074.00 (  0.00%)     4136.00 ( -1.52%)
CPU     NUMA02                3785.00 (  0.00%)     3770.00 (  0.40%)
CPU     NUMA02_SMT            1872.00 (  0.00%)     1959.00 ( -4.65%)

System CPU usage of NUMA01 is worse but it's an adverse workload on this
machine so I'm reluctant to conclude that it's a problem that matters.  On
the other workloads that are sensible on this machine, system CPU usage is
great.  Overall time to complete the benchmark is comparable

          3.18.0-rc5  3.18.0-rc5
        mmotm-20141119protnone-v3r3
User        59612.50    48586.44
System        460.22     1537.45
Elapsed      1442.20     1304.29

NUMA alloc hit                 5075182     5743353
NUMA alloc miss                      0           0
NUMA interleave hit                  0           0
NUMA alloc local               5075174     5743339
NUMA base PTE updates        637061448   443106883
NUMA huge PMD updates          1243434      864747
NUMA page range updates     1273699656   885857347
NUMA hint faults               1658116     1214277
NUMA hint local faults          959487      754113
NUMA hint local percent             57          62
NUMA pages migrated            5467056    61676398

The NUMA pages migrated look terrible but when I looked at a graph of the
activity over time I see that the massive spike in migration activity was
during NUMA01.  This correlates with high system CPU usage and could be
simply down to bad luck but any modifications that affect that workload
would be related to scan rates and migrations, not the protection
mechanism.  For all other workloads, migration activity was comparable.

Overall, headline performance figures are comparable but the overhead is
higher, mostly in interrupts.  To some extent, higher overhead from this
approach was anticipated but not to this degree.  It's going to be
necessary to reduce this again with a separate series in the future.  It's
still worth going ahead with this series though as it's likely to avoid
constant headaches with Xen and is probably easier to maintain.

This patch (of 10):

A transhuge NUMA hinting fault may find the page is migrating and should
wait until migration completes.  The check is race-prone because the pmd
is deferenced outside of the page lock and while the race is tiny, it'll
be larger if the PMD is cleared while marking PMDs for hinting fault.
This patch closes the race.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:08 -08:00
..
backing-dev.c Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block 2014-10-18 11:53:51 -07:00
balloon_compaction.c mm/balloon_compaction: fix deflation when compaction is disabled 2014-10-29 16:33:15 -07:00
bootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
cleancache.c mm: fix cleancache debugfs directory path 2015-01-20 14:08:31 +01:00
cma.c mm: cma: fix totalcma_pages to include DT defined CMA regions 2015-02-11 17:06:03 -08:00
compaction.c mm/compaction: add tracepoint to observe behaviour of compaction defer 2015-02-11 17:06:04 -08:00
debug-pagealloc.c mm/debug-pagealloc: make debug-pagealloc boottime configurable 2014-12-13 12:42:48 -08:00
debug.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
dmapool.c mm/dmapool.c: fixed a brace coding style issue 2014-10-09 22:26:00 -04:00
early_ioremap.c mm: create generic early_ioremap() support 2014-04-07 16:36:15 -07:00
fadvise.c mm: fadvise: document the fadvise(FADV_DONTNEED) behaviour for partial pages 2014-12-13 12:42:49 -08:00
failslab.c
filemap.c mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub 2015-02-10 14:30:30 -08:00
filemap_xip.c mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub 2015-02-10 14:30:30 -08:00
frontswap.c mm/frontswap.c: fix the condition in BUG_ON 2014-12-10 17:41:08 -08:00
gup.c mm: gup: use get_user_pages_unlocked within get_user_pages_fast 2015-02-11 17:06:05 -08:00
highmem.c mm/highmem: make kmap cache coloring aware 2014-08-06 18:01:22 -07:00
huge_memory.c mm: numa: do not dereference pmd outside of the lock during NUMA hinting fault 2015-02-12 18:54:08 -08:00
hugetlb.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
hugetlb_cgroup.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
hwpoison-inject.c mm/hwpoison-inject.c: remove unnecessary null test before debugfs_remove_recursive 2014-08-06 18:01:19 -07:00
init-mm.c
internal.h mm: reduce try_to_compact_pages parameters 2015-02-11 17:06:02 -08:00
interval_tree.c mm: replace vma->sharead.linear with vma->shared 2015-02-10 14:30:31 -08:00
iov_iter.c copy_from_iter_nocache() 2014-12-08 20:25:23 -05:00
Kconfig rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
Kconfig.debug mm/debug_pagealloc: remove obsolete Kconfig options 2015-01-08 15:10:52 -08:00
kmemcheck.c mm/slab_common: move kmem_cache definition to internal header 2014-10-09 22:25:50 -04:00
kmemleak-test.c mm/kmemleak-test.c: use pr_fmt for logging 2014-06-06 16:08:18 -07:00
kmemleak.c mm: introduce kmemleak_update_trace() 2014-06-06 16:08:17 -07:00
ksm.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
list_lru.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
maccess.c
madvise.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
Makefile mm: replace remap_file_pages() syscall with emulation 2015-02-10 14:30:30 -08:00
memblock.c mm/memblock.c: refactor functions to set/clear MEMBLOCK_HOTPLUG 2014-12-13 12:42:46 -08:00
memcontrol.c memcg: cleanup preparation for page table walk 2015-02-11 17:06:06 -08:00
memory-failure.c mm: vmscan: invoke slab shrinkers from shrink_zone() 2014-12-13 12:42:48 -08:00
memory.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
memory_hotplug.c mm, memory_hotplug/failure: drain single zone pcplists 2014-12-10 17:41:05 -08:00
mempolicy.c mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) 2015-02-11 17:06:06 -08:00
mempool.c mm/mempool.c: update the kmemleak stack trace for mempool allocations 2014-06-06 16:08:17 -07:00
migrate.c mm: numa: do not dereference pmd outside of the lock during NUMA hinting fault 2015-02-12 18:54:08 -08:00
mincore.c mincore: apply page table walker on do_mincore() 2015-02-11 17:06:06 -08:00
mlock.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-10-13 15:44:12 +02:00
mm_init.c mm: bring back /sys/kernel/mm 2014-01-27 21:02:39 -08:00
mmap.c mm/mmap.c: fix arithmetic overflow in __vm_enough_memory() 2015-02-11 17:06:07 -08:00
mmu_context.c sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm 2014-02-21 08:50:17 +01:00
mmu_notifier.c mmu_notifier: add the callback for mmu_notifier_invalidate_range() 2014-11-13 13:46:09 +11:00
mmzone.c mm: microoptimize zonelist operations 2015-02-11 17:06:02 -08:00
mprotect.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
mremap.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
msync.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
nobootmem.c mem-hotplug: reset node managed pages when hot-adding a new pgdat 2014-11-13 16:17:06 -08:00
nommu.c mm/nommu.c: fix arithmetic overflow in __vm_enough_memory() 2015-02-11 17:06:07 -08:00
oom_kill.c mm: account pmd page tables to the process 2015-02-11 17:06:04 -08:00
page-writeback.c page_writeback: put account_page_redirty() after set_page_dirty() 2015-02-11 17:06:04 -08:00
page_alloc.c mm: more aggressive page stealing for UNMOVABLE allocations 2015-02-11 17:06:06 -08:00
page_counter.c mm: page_counter: pull "-1" handling out of page_counter_memparse() 2015-02-11 17:06:02 -08:00
page_ext.c mm/page_owner: keep track of page owners 2014-12-13 12:42:48 -08:00
page_io.c fix __swap_writepage() compile failure on old gcc versions 2014-06-14 19:30:48 -05:00
page_isolation.c mm, page_isolation: drain single zone pcplists 2014-12-10 17:41:05 -08:00
page_owner.c mm/page_owner.c: remove unnecessary stack_trace field 2015-02-11 17:06:07 -08:00
pagewalk.c mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP) 2015-02-11 17:06:06 -08:00
percpu-km.c percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated 2014-09-02 14:46:05 -04:00
percpu-vm.c percpu: move region iterations out of pcpu_[de]populate_chunk() 2014-09-02 14:46:02 -04:00
percpu.c percpu: off by one in BUG_ON() 2014-10-29 10:34:34 -04:00
pgtable-generic.c mm: actually clear pmd_numa before invalidating 2014-08-29 16:28:15 -07:00
process_vm_access.c mm: gup: use get_user_pages_unlocked 2015-02-11 17:06:05 -08:00
quicklist.c
readahead.c mm/readahead.c: remove unused file_ra_state from count_history_pages 2014-08-06 18:01:15 -07:00
rmap.c mm: memcontrol: track move_lock state internally 2015-02-11 17:06:00 -08:00
shmem.c swap: remove unused mem_cgroup_uncharge_swapcache declaration 2015-02-11 17:06:00 -08:00
slab.c slab: fix cpuset check in fallback_alloc 2014-12-13 12:42:53 -08:00
slab.h memcg: zap __memcg_{charge,uncharge}_slab 2015-02-10 14:30:34 -08:00
slab_common.c memcg: zap memcg_slab_caches and memcg_slab_mutex 2015-02-10 14:30:34 -08:00
slob.c mm/sl[ao]b: always track caller in kmalloc_(node_)track_caller() 2014-10-09 22:25:50 -04:00
slub.c mm/slub.c: fix typo in comment 2015-02-10 14:30:30 -08:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:35:54 -07:00
swap.c rmap: drop support of non-linear mappings 2015-02-10 14:30:31 -08:00
swap_cgroup.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
swap_state.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
swapfile.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
truncate.c mm: Fix comment before truncate_setsize() 2014-11-07 08:29:25 +11:00
util.c mm: gup: use get_user_pages_unlocked within get_user_pages_fast 2015-02-11 17:06:05 -08:00
vmacache.c mm,vmacache: count number of system-wide flushes 2014-12-13 12:42:48 -08:00
vmalloc.c mm/vmalloc.c: fix memory ordering bug 2014-12-13 12:42:49 -08:00
vmpressure.c mm/vmpressure.c: fix race in vmpressure_work_fn() 2014-12-02 17:32:07 -08:00
vmscan.c mm: memcontrol: default hierarchy interface for memory 2015-02-11 17:06:02 -08:00
vmstat.c vmstat: Reduce time interval to stat update on idle cpu 2015-02-11 17:06:07 -08:00
workingset.c mm: keep page cache radix tree nodes in check 2014-04-03 16:21:01 -07:00
zbud.c mm/zbud: init user ops only when it is needed 2014-12-13 12:42:51 -08:00
zpool.c mm/zpool: use prefixed module loading 2014-08-29 16:28:16 -07:00
zsmalloc.c mm/zsmalloc: adjust order of functions 2014-12-18 19:08:11 -08:00
zswap.c mm/zswap: delete unnecessary check before calling free_percpu() 2014-12-13 12:42:50 -08:00