linux/mm
Kirill A. Shutemov b35f1819ac mm: create a separate slab for page->ptl allocation
If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes.  For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each.  An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.

Let's create a separate slab for page->ptl allocation to solve this.

To make sure that it really works this time, some numbers from my test
machine (just booted, no load):

Before:
  # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
  kmalloc-96         31987  32190    128   30    1 : tunables  120   60    8 : slabdata   1073   1073     92
After:
  # grep '^\(kmalloc-96\|page->ptl\)' /proc/slabinfo
  page->ptl          27516  28143     72   53    1 : tunables  120   60    8 : slabdata    531    531      9
  kmalloc-96          3853   5280    128   30    1 : tunables  120   60    8 : slabdata    176    176      0

Note that the patch is useful not only for debug case, but also for
PREEMPT_RT, where spinlock_t is always bloated.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21 16:19:44 -08:00
..
Kconfig mm: add missing dependency in Kconfig 2013-12-18 19:04:52 -08:00
Kconfig.debug
Makefile
backing-dev.c mm/backing-dev.c: check user buffer length before copying data to the related user buffer 2013-09-11 15:58:03 -07:00
balloon_compaction.c
bootmem.c mm/bootmem.c: remove unused local `map' 2013-11-13 12:09:09 +09:00
bounce.c mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was ignored 2013-09-30 14:31:02 -07:00
cleancache.c
compaction.c mm/compaction: respect ignore_skip_hint in update_pageblock_skip 2013-12-18 19:04:52 -08:00
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c
filemap.c mm: drop actor argument of do_generic_file_read() 2013-11-15 09:32:13 +09:00
filemap_xip.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fremap.c mm: fix use-after-free in sys_remap_file_pages 2014-01-02 14:40:30 -08:00
frontswap.c
highmem.c
huge_memory.c thp: fix copy_page_rep GPF by testing is_huge_zero_pmd once only 2014-01-12 16:47:15 +07:00
hugetlb.c mm/hugetlb.c: defer PageHeadHuge() symbol export 2014-01-21 16:19:43 -08:00
hugetlb_cgroup.c
hwpoison-inject.c mm/hwpoison: fix the lack of one reference count against poisoned page 2013-09-30 14:31:03 -07:00
init-mm.c
internal.h mm: thp: __get_page_tail_foll() can use get_huge_page_tail() 2014-01-21 16:19:43 -08:00
interval_tree.c
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: kmemleak: avoid false negatives on vmalloc'ed objects 2013-11-13 12:09:07 +09:00
ksm.c ksm: remove redundant __GFP_ZERO from kcalloc 2013-11-13 12:09:02 +09:00
list_lru.c mm: list_lru: fix almost infinite loop causing effective livelock 2013-10-30 12:57:46 -07:00
maccess.c
madvise.c mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk flood 2013-09-30 14:31:02 -07:00
memblock.c mm/memblock.c: introduce bottom-up allocation mode 2013-11-13 12:09:08 +09:00
memcontrol.c memcg: fix memcg_size() calculation 2014-01-02 14:40:30 -08:00
memory-failure.c mm/memory-failure.c: transfer page count from head page to tail page after split thp 2014-01-02 14:40:30 -08:00
memory.c mm: create a separate slab for page->ptl allocation 2014-01-21 16:19:44 -08:00
memory_hotplug.c mem-hotplug: introduce movable_node boot option 2013-11-13 12:09:09 +09:00
mempolicy.c mm/mempolicy: fix !vma in new_vma_page() 2013-12-18 19:04:52 -08:00
mempool.c mm/mempool.c: convert kmalloc_node(...GFP_ZERO...) to kzalloc_node(...) 2013-09-11 15:58:14 -07:00
migrate.c aio/migratepages: make aio migrate pages sane 2013-12-21 17:56:08 -05:00
mincore.c
mlock.c mm: munlock: fix deadlock in __munlock_pagevec() 2014-01-02 14:40:30 -08:00
mm_init.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mmap.c mm: convert mm->nr_ptes to atomic_long_t 2013-11-15 09:32:14 +09:00
mmu_context.c
mmu_notifier.c
mmzone.c mm: numa: Change page last {nid,pid} into {cpu,pid} 2013-10-09 14:47:45 +02:00
mprotect.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
mremap.c mm: revert mremap pud_free anti-fix 2013-10-16 21:35:53 -07:00
msync.c
nobootmem.c mm/nobootmem.c: have __free_pages_memory() free in larger chunks. 2013-11-13 12:09:04 +09:00
nommu.c Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
oom_kill.c mm: convert mm->nr_ptes to atomic_long_t 2013-11-15 09:32:14 +09:00
page-writeback.c writeback: fix negative bdi max pause 2013-10-16 21:35:53 -07:00
page_alloc.c mm: get rid of unnecessary pageblock scanning in setup_zone_migrate_reserve 2014-01-21 16:19:43 -08:00
page_cgroup.c
page_io.c
page_isolation.c
pagewalk.c mm/pagewalk.c: fix walk_page_range() access of wrong PTEs 2013-10-30 14:27:03 -07:00
percpu-km.c
percpu-vm.c
percpu.c percpu: fix bootmem error handling in pcpu_page_first_chunk() 2013-09-23 10:51:45 -04:00
pgtable-generic.c mm: fix TLB flush race between migration, and change_protection_range 2013-12-18 19:04:51 -08:00
process_vm_access.c
quicklist.c
readahead.c readahead: fix sequential read cache miss detection 2013-11-13 12:09:09 +09:00
rmap.c mm/hugetlb: check for pte NULL pointer in __page_check_address() 2013-12-18 19:04:52 -08:00
shmem.c security: shmem: implement kernel private shmem inodes 2013-12-02 11:24:19 +00:00
slab.c Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-11-22 08:10:34 -08:00
slab.h memcg, kmem: rename cache_from_memcg to cache_from_memcg_idx 2013-11-13 12:09:10 +09:00
slab_common.c memcg, kmem: rename cache_from_memcg to cache_from_memcg_idx 2013-11-13 12:09:10 +09:00
slob.c
slub.c Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2013-11-22 08:10:34 -08:00
sparse-vmemmap.c
sparse.c mm/sparsemem: fix a bug in free_map_bootmem when CONFIG_SPARSEMEM_VMEMMAP 2013-11-13 12:09:06 +09:00
swap.c mm/swap.c: reorganize put_compound_page() 2014-01-21 16:19:43 -08:00
swap_state.c lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interrupt 2013-09-11 15:59:36 -07:00
swapfile.c frontswap: enable call to invalidate area on swapoff 2013-11-13 12:09:07 +09:00
truncate.c truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
util.c mm: fix crash when using XFS on loopback 2014-01-15 14:19:42 +07:00
vmalloc.c mm: kmemleak: avoid false negatives on vmalloc'ed objects 2013-11-13 12:09:07 +09:00
vmpressure.c
vmscan.c mm/vmscan.c: don't forget to free shrinker->nr_deferred 2013-10-16 21:35:52 -07:00
vmstat.c mm: numa: return the number of base pages altered by protection changes 2013-11-13 12:09:11 +09:00
zbud.c
zswap.c mm/zswap: refactor the get/put routines 2013-11-13 12:09:11 +09:00