linux/mm
Kirill A. Shutemov 97ae17497e thp: implement refcounting for huge zero page
H.  Peter Anvin doesn't like huge zero page which sticks in memory forever
after the first allocation.  Here's implementation of lockless refcounting
for huge zero page.

We have two basic primitives: {get,put}_huge_zero_page(). They
manipulate reference counter.

If counter is 0, get_huge_zero_page() allocates a new huge page and takes
two references: one for caller and one for shrinker.  We free the page
only in shrinker callback if counter is 1 (only shrinker has the
reference).

put_huge_zero_page() only decrements counter.  Counter is never zero in
put_huge_zero_page() since shrinker holds on reference.

Freeing huge zero page in shrinker callback helps to avoid frequent
allocate-free.

Refcounting has cost.  On 4 socket machine I observe ~1% slowdown on
parallel (40 processes) read page faulting comparing to lazy huge page
allocation.  I think it's pretty reasonable for synthetic benchmark.

[lliubbo@gmail.com: fix mismerge]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12 17:38:31 -08:00
..
backing-dev.c backing-dev: use kstrto* in preference to simple_strtoul 2012-08-25 16:58:14 +08:00
balloon_compaction.c mm: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
bootmem.c bootmem: remove alloc_arch_preferred_bootmem() 2012-12-12 17:38:31 -08:00
bounce.c bounce: allow use of bounce pool via config option 2012-07-18 16:40:35 -04:00
cleancache.c ->encode_fh() API change 2012-05-29 23:28:33 -04:00
compaction.c mm: introduce putback_movable_pages() 2012-12-11 17:22:27 -08:00
debug-pagealloc.c
dmapool.c dmapool: make DMAPOOL_DEBUG detect corruption of free marker 2012-12-11 17:22:24 -08:00
fadvise.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c readahead: fault retry breaks mmap file read random detection 2012-10-09 16:22:47 +09:00
filemap_xip.c mm: move all mmu notifier invocations to be done outside the PT lock 2012-10-09 16:22:58 +09:00
fremap.c remap_file_pages: correctly handle the case of a NULL vm_ops pointer 2012-10-19 13:37:57 -07:00
frontswap.c frontswap: support exclusive gets if tmem backend is capable 2012-09-21 10:38:12 -04:00
highmem.c mm, highmem: get virtual address of the page using PKMAP_ADDR() 2012-12-11 17:22:24 -08:00
huge_memory.c thp: implement refcounting for huge zero page 2012-12-12 17:38:31 -08:00
hugetlb.c numa: convert static memory to dynamically allocated memory for per node device 2012-12-11 17:22:23 -08:00
hugetlb_cgroup.c cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
hwpoison-inject.c memcg: rename config variables 2012-07-31 18:42:43 -07:00
init-mm.c
internal.h mm: introduce mm_find_pmd() 2012-12-11 17:22:22 -08:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
Kconfig mm: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c
kmemleak.c kmemleak: use rbtree instead of prio tree 2012-10-09 16:22:39 +09:00
ksm.c mm, oom: fix race when specifying a thread as the oom origin 2012-12-11 17:22:27 -08:00
maccess.c
madvise.c mm: prepare VM_DONTDUMP for using in drivers 2012-10-09 16:22:18 +09:00
Makefile mm: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
memblock.c x86, mm: Trim memory in memblock to be page aligned 2012-10-24 11:52:21 -07:00
memcontrol.c Merge branch 'for-3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-12-12 08:18:24 -08:00
memory-failure.c mm: hwpoison: fix action_result() to print out dirty/clean 2012-12-11 17:22:24 -08:00
memory.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
memory_hotplug.c memory_hotplug: ensure every online node has NORMAL memory 2012-12-11 17:22:28 -08:00
mempolicy.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
mempool.c mempool: add @gfp_mask to mempool_create_node() 2012-06-25 11:53:47 +02:00
migrate.c mm: introduce putback_movable_pages() 2012-12-11 17:22:27 -08:00
mincore.c mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode 2012-03-21 17:54:54 -07:00
mlock.c mm, thp: fix mlock statistics 2012-10-09 16:23:03 +09:00
mm_init.c
mmap.c Merge branch 'akpm' (Andrew's patchbomb) 2012-12-11 18:05:37 -08:00
mmu_context.c mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat() 2012-03-21 17:54:59 -07:00
mmu_notifier.c mm/mmu_notifier: allocate mmu_notifier in advance 2012-10-25 14:37:53 -07:00
mmzone.c memcg: fix hotplugged memory zone oops 2012-11-16 14:33:04 -08:00
mprotect.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
mremap.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
msync.c
nobootmem.c revert "mm: fix-up zone present pages" 2012-11-16 14:33:04 -08:00
nommu.c mm: export a function to get vm committed memory 2012-11-15 15:41:22 -08:00
oom_kill.c mm, oom: fix race when specifying a thread as the oom origin 2012-12-11 17:22:27 -08:00
page-writeback.c writeback: remove nr_pages_dirtied arg from balance_dirty_pages_ratelimited_nr() 2012-12-11 17:22:21 -08:00
page_alloc.c mm: cma: remove watermark hacks 2012-12-11 17:22:27 -08:00
page_cgroup.c memory-hotplug: auto offline page_cgroup when onlining memory block failed 2012-12-11 17:22:23 -08:00
page_io.c mm: add support for direct_IO to highmem pages 2012-07-31 18:42:47 -07:00
page_isolation.c memory-hotplug: skip HWPoisoned page when offlining pages 2012-12-11 17:22:22 -08:00
pagewalk.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
percpu-km.c
percpu-vm.c mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
percpu.c mm, percpu: Make sure percpu_alloc early parameter has an argument 2012-12-02 06:23:04 -08:00
pgtable-generic.c thp: introduce pmdp_invalidate() 2012-10-09 16:22:29 +09:00
process_vm_access.c aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector() 2012-05-31 17:49:32 -07:00
quicklist.c
readahead.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
rmap.c mm: add comment on storage key dirty bit semantics 2012-12-11 17:22:23 -08:00
shmem.c tmpfs: fix shared mempolicy leak 2012-12-06 11:56:43 -08:00
slab.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2012-10-07 07:53:13 +09:00
slab.h Revert "mm/sl[aou]b: Move sysfs_slab_add to common" 2012-09-05 12:07:44 +03:00
slab_common.c mm, slab: release slab_mutex earlier in kmem_cache_destroy() 2012-10-10 09:25:08 +03:00
slob.c Merge branch 'testing/driver-warnings' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes 2012-10-19 15:40:18 -07:00
slub.c slub, hotplug: ignore unrelated node's hot-adding and hot-removing 2012-12-11 17:22:23 -08:00
sparse-vmemmap.c
sparse.c memory-hotplug, mm/sparse.c: clear the memory to store struct page 2012-12-11 17:22:23 -08:00
swap.c mm: remove vma arg from page_evictable 2012-10-09 16:22:55 +09:00
swap_state.c mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages 2012-07-31 18:42:47 -07:00
swapfile.c mm, oom: fix race when specifying a thread as the oom origin 2012-12-11 17:22:27 -08:00
truncate.c mm: use clear_page_mlock() in page_remove_rmap() 2012-10-09 16:22:56 +09:00
util.c mm: Use __do_krealloc to do the krealloc job 2012-09-04 10:22:58 +03:00
vmalloc.c mm: use IS_ENABLED(CONFIG_NUMA) instead of NUMA_BUILD 2012-12-11 17:22:22 -08:00
vmscan.c mm/vmscan.c: try_to_freeze() returns boolean 2012-12-11 17:22:27 -08:00
vmstat.c mm: remove unevictable_pgs_mlockfreed 2012-10-09 16:22:59 +09:00