linux/mm
Bo Liu 32c5fc10e7 mm: remove incorrect swap_count() from try_to_unuse()
In try_to_unuse(), swcount is a local copy of *swap_map, including the
SWAP_HAS_CACHE bit; but a wrong comparison against swap_count(*swap_map),
which masks off the SWAP_HAS_CACHE bit, succeeded where it should fail.

That had the effect of resetting the mm from which to start searching
for the next swap page, to an irrelevant mm instead of to an mm in which
this swap page had been found: which may increase search time by ~20%.
But we're used to swapoff being slow, so never noticed the slowdown.

Remove that one spurious use of swap_count(): Bo Liu thought it merely
redundant, Hugh rewrote the description since it was measurably wrong.

Signed-off-by: Bo Liu <bo-liu@hotmail.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-02 09:44:41 -08:00
..
allocpercpu.c percpu: use dynamic percpu allocator as the default percpu allocator 2009-06-24 15:13:35 +09:00
backing-dev.c backing-dev: ensure that a removed bdi no longer has super_block referencing it 2009-10-29 11:46:12 +01:00
bootmem.c kmemleak: Do not report alloc_bootmem blocks as leaks 2009-08-27 14:29:17 +01:00
bounce.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
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: move max_sane_readahead() calls into force_page_cache_readahead() 2009-06-16 19:47:28 -07:00
failslab.c kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c 2009-04-03 12:23:01 +02:00
filemap_xip.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
filemap.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
fremap.c Do not account for the address space used by hugetlbfs using VM_ACCOUNT 2009-02-10 10:48:42 -08:00
highmem.c block: remove some includings of blktrace_api.h 2009-06-16 11:19:36 +02:00
hugetlb.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
hwpoison-inject.c HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs 2009-09-16 11:50:17 +02:00
init-mm.c mm: consolidate init_mm definition 2009-06-16 19:47:28 -07:00
internal.h mm: move highest_memmap_pfn 2009-09-22 07:17:41 -07:00
Kconfig Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2009-10-29 08:59:06 -07:00
Kconfig.debug trivial: improve help text for mm debug config options 2009-09-21 15:14:57 +02:00
kmemcheck.c kmemcheck: add hooks for the page allocator 2009-06-15 15:48:33 +02:00
kmemleak-test.c percpu: clean up percpu variable definitions 2009-06-24 15:13:48 +09:00
kmemleak.c kmemleak: Check for NULL pointer returned by create_object() 2009-10-09 13:28:47 -07:00
ksm.c ksm: more on default values 2009-10-08 07:36:38 -07:00
maccess.c [S390] maccess: add weak attribute to probe_kernel_write 2009-06-12 10:27:37 +02:00
madvise.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
Makefile procfs: disable per-task stack usage on NOMMU 2009-09-24 17:11:24 -07:00
memcontrol.c memcg: reduce check for softlimit excess 2009-10-01 16:11:13 -07:00
memory_hotplug.c walk system ram range 2009-09-23 07:39:41 -07:00
memory-failure.c hwpoison: fix oops on ksm pages 2009-10-29 07:39:24 -07:00
memory.c Merge branch 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-10-29 08:20:00 -07:00
mempolicy.c do_mbind(): fix memory leak 2009-10-29 07:39:29 -07:00
mempool.c mm: remove broken 'kzalloc' mempool 2009-09-22 07:17:35 -07:00
migrate.c Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 2009-09-24 07:53:22 -07:00
mincore.c [CVE-2009-0029] System call wrappers part 14 2009-01-14 14:15:24 +01:00
mlock.c mm: m(un)lock avoid ZERO_PAGE 2009-09-22 07:17:40 -07:00
mm_init.c mm: mminit_loglevel cannot be __meminitdata anymore 2008-08-20 15:40:30 -07:00
mmap.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
mmu_context.c mm: reduce atomic use on use_mm fast path 2009-09-22 07:17:42 -07:00
mmu_notifier.c ksm: add mmu_notifier set_pte_at_notify() 2009-09-22 07:17:31 -07:00
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 perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
mremap.c truncate: new helpers 2009-09-24 08:41:47 -04:00
msync.c [CVE-2009-0029] System call wrappers part 13 2009-01-14 14:15:23 +01:00
nommu.c NOMMU: Don't pass NULL pointers to fput() in do_mmap_pgoff() 2009-10-31 12:11:37 -07:00
oom_kill.c oom: oom_kill doesn't kill vfork parent (or child) 2009-09-22 07:17:39 -07:00
page_alloc.c revert "mm: oom analysis: add buffer cache information to show_free_areas()" 2009-10-29 07:39:27 -07:00
page_cgroup.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
page_io.c mm: remove file argument from swap_readpage() 2009-06-16 19:47:44 -07:00
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: account IO throttling wait as iowait 2009-10-09 12:40:42 +02:00
pagewalk.c pagemap: pass mm into pagewalkers 2008-06-12 18:05:41 -07:00
percpu.c percpu: allow pcpu_alloc() to be called with IRQs off 2009-10-29 00:25:59 +09:00
prio_tree.c
quicklist.c cpumask: use new-style cpumask ops in mm/quicklist. 2009-09-24 09:34:52 +09:30
readahead.c readahead: introduce context readahead algorithm 2009-06-16 19:47:30 -07:00
rmap.c mm/rmap.c: fix comment 2009-10-01 16:11:12 -07:00
shmem_acl.c shmfs: use 'check_acl' instead of 'permission' 2009-09-08 11:08:46 -07:00
shmem.c const: mark struct vm_struct_operations 2009-09-27 11:39:25 -07:00
slab.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
slob.c slab: remove duplicate kmem_cache_init_late() declarations 2009-08-06 11:36:25 +03:00
slub.c mm: kmem_cache_create(): make it easier to catch NULL cache names 2009-09-22 07:17:33 -07:00
sparse-vmemmap.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
sparse.c memory hotplug: alloc page from other node in memory online 2009-09-22 07:17:26 -07:00
swap_state.c mm: add_to_swap_cache() does not return -EEXIST 2009-09-22 07:17:35 -07:00
swap.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
swapfile.c mm: remove incorrect swap_count() from try_to_unuse() 2009-11-02 09:44:41 -08:00
thrash.c mm: pass mm to grab_swap_token 2009-06-23 12:50:05 -07:00
truncate.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-09-24 08:32:11 -07:00
util.c Merge branches 'slab/documentation', 'slab/fixes', 'slob/cleanups' and 'slub/fixes' into for-linus 2009-06-17 08:30:15 +03:00
vmalloc.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
vmscan.c vmscan: order evictable rescue in LRU putback 2009-10-29 07:39:30 -07:00
vmstat.c mm: vmstat: add isolate pages 2009-09-22 07:17:29 -07:00