linux/mm
Tim Chen 7e496299d4 tmpfs: make tmpfs scalable with percpu_counter for used blocks
The current implementation of tmpfs is not scalable.  We found that
stat_lock is contended by multiple threads when we need to get a new page,
leading to useless spinning inside this spin lock.

This patch makes use of the percpu_counter library to maintain local count
of used blocks to speed up getting and returning of pages.  So the
acquisition of stat_lock is unnecessary for getting and returning blocks,
improving the performance of tmpfs on system with large number of cpus.
On a 4 socket 32 core NHM-EX system, we saw improvement of 270%.

The implementation below has a slight chance of race between threads
causing a slight overshoot of the maximum configured blocks.  However, any
overshoot is small, and is bounded by the number of cpus.  This happens
when the number of used blocks is slightly below the maximum configured
blocks when a thread checks the used block count, and another thread
allocates the last block before the current thread does.  This should not
be a problem for tmpfs, as the overshoot is most likely to be a few blocks
and bounded.  If a strict limit is really desired, then configured the max
blocks to be the limit less the number of cpus in system.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:44:58 -07:00
..
backing-dev.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 09:23:07 -07:00
bootmem.c x86,nobootmem: make alloc_bootmem_node fall back to other node when 32bit numa is used 2010-07-20 16:25:40 -07:00
bounce.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
compaction.c mm: compaction: add a tunable that decides when memory should be compacted and when it should be reclaimed 2010-05-25 08:06:59 -07:00
debug-pagealloc.c generic debug pagealloc 2009-04-01 08:59:13 -07:00
dmapool.c dmapools: protect page_list walk in show_pools() 2009-06-30 18:56:00 -07:00
fadvise.c readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM 2010-03-06 11:26:25 -08:00
failslab.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap_xip.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap.c gcc-4.6: mm: fix unused but set warnings 2010-08-09 20:44:58 -07:00
fremap.c mm: clean up mm_counter 2010-03-06 11:26:23 -08:00
highmem.c mm,kdb,kgdb: Add a debug reference for the kdb kmap usage 2010-08-05 09:22:24 -05:00
hugetlb.c hugetlb: call mmu notifiers on hugepage cow 2010-08-09 20:44:54 -07:00
hwpoison-inject.c HWPOISON: Don't do early filtering if filter is disabled 2009-12-16 12:20:01 +01:00
init-mm.c mm: provide init_mm mm_context initializer 2010-08-09 20:44:54 -07:00
internal.h HWPOISON: add an interface to switch off/on all the page filters 2009-12-16 12:19:59 +01:00
Kconfig lmb: rename to memblock 2010-07-14 17:14:00 +10:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ksm.c mm: extend KSM refcounts to the anon_vma root 2010-08-09 20:44:55 -07:00
maccess.c maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write) 2010-01-07 11:58:36 -06:00
madvise.c HWPOISON: Add a madvise() injector for soft page offlining 2009-12-16 12:20:00 +01:00
Makefile lmb: rename to memblock 2010-07-14 17:14:00 +10:00
memblock.c lmb: rename to memblock 2010-07-14 17:14:00 +10:00
memcontrol.c memcg: fix wake up in oom wait queue 2010-06-29 15:29:30 -07:00
memory_hotplug.c mem-hotplug: fix potential race while building zonelist for new populated zone 2010-05-25 08:07:02 -07:00
memory-failure.c KVM: Fix a race condition for usage of is_hwpoison_address() 2010-08-01 10:47:11 +03:00
memory.c gcc-4.6: mm: fix unused but set warnings 2010-08-09 20:44:58 -07:00
mempolicy.c mempolicy: reduce stack size of migrate_pages() 2010-08-09 20:44:58 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c mm: extend KSM refcounts to the anon_vma root 2010-08-09 20:44:55 -07:00
mincore.c mincore: do nested page table walks 2010-05-25 08:06:58 -07:00
mlock.c x86, perf, bts, mm: Delete the never used BTS-ptrace code 2010-03-26 11:33:55 +01:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c mm: always lock the root (oldest) anon_vma 2010-08-09 20:44:55 -07:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mmzone.c [ARM] Double check memmap is actually valid with a memmap has unexpected holes V2 2009-05-18 11:22:24 +01:00
mprotect.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mremap.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nommu.c nommu: allow private mappings of read-only devices 2010-05-26 08:19:23 -07:00
oom_kill.c oom: fold __out_of_memory into out_of_memory 2010-08-09 20:44:57 -07:00
page_alloc.c mm: rename try_set_zone_oom() to try_set_zonelist_oom() 2010-08-09 20:44:57 -07:00
page_cgroup.c kmemleak: Annotate false positive in init_section_page_cgroup() 2010-07-19 11:54:14 +01:00
page_io.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
page_isolation.c memory hotplug: fix page_zone() calculation in test_pages_isolated() 2008-11-06 15:41:19 -08:00
page-writeback.c writeback: remove writeback_inodes_wbc 2010-07-06 08:54:03 +02:00
pagewalk.c pagemap: fix pfn calculation for hugepage 2010-04-07 08:38:04 -07:00
percpu_up.c percpu: don't implicitly include slab.h from percpu.h 2010-03-30 22:02:32 +09:00
percpu-km.c percpu: implement kernel memory based chunk allocation 2010-05-01 08:30:50 +02:00
percpu-vm.c percpu: move vmalloc based chunk management into percpu-vm.c 2010-05-01 08:30:50 +02:00
percpu.c percpu: allow limited allocation before slab is online 2010-06-27 18:50:00 +02:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
readahead.c readahead.c: fix comment 2010-05-25 08:07:00 -07:00
rmap.c mm: extend KSM refcounts to the anon_vma root 2010-08-09 20:44:55 -07:00
shmem.c tmpfs: make tmpfs scalable with percpu_counter for used blocks 2010-08-09 20:44:58 -07:00
slab.c gcc-4.6: mm: fix unused but set warnings 2010-08-09 20:44:58 -07:00
slob.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-08-06 11:44:08 -07:00
slub.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 2010-08-06 11:44:08 -07:00
sparse-vmemmap.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
sparse.c sparsemem: on no vmemmap path put mem_map on node high too 2010-05-25 08:06:56 -07:00
swap_state.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
swap.c mm: export lru_cache_add_*() to modules 2010-05-25 15:06:06 +02:00
swapfile.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6 2010-05-21 15:26:46 -07:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c fs: introduce new truncate sequence 2010-05-27 22:15:33 -04:00
util.c mm: use memdup_user 2010-08-09 20:44:54 -07:00
vmalloc.c mm: use ERR_CAST 2010-08-09 20:44:54 -07:00
vmscan.c mm/vmscan.c: fix mapping use after free 2010-07-20 16:25:40 -07:00
vmstat.c mm: use for_each_online_cpu() in vmstat 2010-08-09 20:44:57 -07:00