aha/mm
Matthew Wilcox 80cbd911ca Fix kmem_cache_free performance regression in slab
The database performance group have found that half the cycles spent
in kmem_cache_free are spent in this one call to BUG_ON.  Moving it
into the CONFIG_SLAB_DEBUG-only function cache_free_debugcheck() is a
performance win of almost 0.5% on their particular benchmark.

The call was added as part of commit ddc2e812d5
with the comment that "overhead should be minimal".  It may have been
minimal at the time, but it isn't now.

[ Quoth Pekka Enberg: "I don't think the BUG_ON per se caused the
  performance regression but rather the virt_to_head_page() changes to
  virt_to_cache() that were added later." ]

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Pekka J Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-30 08:08:05 -08:00
..
allocpercpu.c Slab allocators: Replace explicit zeroing with __GFP_ZERO 2007-07-17 10:23:02 -07:00
backing-dev.c mm: per device dirty threshold 2007-10-17 08:42:45 -07:00
bootmem.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
bounce.c block: Initial support for data-less (or empty) barrier support 2007-10-16 11:03:56 +02:00
fadvise.c [PATCH] mm: change uses of f_{dentry,vfsmnt} to use f_path 2006-12-08 08:28:43 -08:00
filemap.c Remove broken ptrace() special-case code from file mapping 2007-10-31 09:19:46 -07:00
filemap_xip.c mm: write iovec cleanup 2007-10-16 09:42:54 -07:00
fremap.c remap_file_pages: kernel-doc corrections 2007-10-17 08:43:07 -07:00
highmem.c Create the ZONE_MOVABLE zone 2007-07-17 10:22:59 -07:00
hugetlb.c hugetlb: fix i_blocks accounting 2007-11-14 18:45:40 -08:00
internal.h Breakout page_order() to internal.h to avoid special knowledge of the buddy allocator 2007-10-16 09:43:01 -07:00
Kconfig small documentation fixes 2007-10-20 02:46:58 +02:00
madvise.c speed up madvise_need_mmap_write() usage 2007-07-16 09:05:36 -07:00
Makefile memory unplug: page isolation 2007-10-16 09:43:02 -07:00
memory.c Swap delay accounting, include lock_page() delays 2007-11-14 18:45:44 -08:00
memory_hotplug.c Add IORESOUCE_BUSY flag for System RAM 2007-11-14 18:45:39 -08:00
mempolicy.c Migration: find correct vma in new_vma_page() 2007-11-14 18:45:38 -08:00
mempool.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
migrate.c Typo fixes retrun -> return 2007-10-20 02:13:26 +02:00
mincore.c [PATCH] mincore: vma crossing fix 2007-02-15 09:57:03 -08:00
mlock.c do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY 2007-07-16 09:05:37 -07:00
mmap.c fix mprotect vma_wants_writenotify prot 2007-10-23 08:32:06 -07:00
mmzone.c [PATCH] remove EXPORT_UNUSED_SYMBOL'ed symbols 2006-12-07 08:39:44 -08:00
mprotect.c fix mprotect vma_wants_writenotify prot 2007-10-23 08:32:06 -07:00
mremap.c sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
msync.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
nommu.c NOMMU: mm/nommu.c needs linux/module.h 2007-10-29 07:53:26 -07:00
oom_kill.c oom_kill bug 2007-10-20 15:04:06 -07:00
page-writeback.c dirty page balancing: Get rid of broken unmapped_ratio logic 2007-11-15 16:41:52 -08:00
page_alloc.c Fix boot problem with iSeries lacking hugepage support 2007-11-29 09:24:51 -08:00
page_io.c Drop 'size' argument from bio_endio and bi_end_io 2007-10-10 09:25:57 +02:00
page_isolation.c memory hotremove: unset migrate type "ISOLATE" after removal 2007-11-14 18:45:38 -08:00
pdflush.c Freezer: make kernel threads nonfreezable by default 2007-07-17 10:23:02 -07:00
prio_tree.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
quicklist.c Quicklists for page table pages 2007-05-07 12:12:54 -07:00
readahead.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
rmap.c [S390] Optimize storage key handling for anonymous pages 2007-11-20 11:13:46 +01:00
shmem.c tmpfs: restore missing clear_highpage 2007-11-28 11:04:28 -08:00
shmem_acl.c [PATCH] Fix typos in mm/shmem_acl.c 2006-10-11 11:14:23 -07:00
slab.c Fix kmem_cache_free performance regression in slab 2007-11-30 08:08:05 -08:00
slob.c slob: fix memory corruption 2007-11-15 08:36:27 -08:00
slub.c SLUB: killed the unused "end" variable 2007-11-12 10:32:29 -08:00
sparse-vmemmap.c memory hotplug fix: fix section mismatch in vmammap_allock_block() 2007-11-29 09:24:54 -08:00
sparse.c Revert "x86_64: allocate sparsemem memmap above 4G" 2007-10-29 14:05:37 -07:00
swap.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
swap_state.c mm: clarify __add_to_swap_cache locking 2007-10-16 09:42:53 -07:00
swapfile.c Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION 2007-07-29 16:45:38 -07:00
thrash.c Bug in mm/thrash.c function grab_swap_token() 2007-05-11 08:29:32 -07:00
tiny-shmem.c r/o bind mounts: filesystem helpers for custom 'struct file's 2007-10-17 08:43:04 -07:00
truncate.c Drop some headers from mm.h 2007-10-17 08:42:55 -07:00
util.c fix mm/util.c:krealloc() 2007-11-14 18:45:41 -08:00
vmalloc.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
vmscan.c spelling fixes: mm/ 2007-10-20 01:27:18 +02:00
vmstat.c vmstat: fix section mismatch warning 2007-11-14 18:45:42 -08:00