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Kirill A. Shutemov ddc58f27f9 mm: drop tail page refcounting
Tail page refcounting is utterly complicated and painful to support.

It uses ->_mapcount on tail pages to store how many times this page is
pinned.  get_page() bumps ->_mapcount on tail page in addition to
->_count on head.  This information is required by split_huge_page() to
be able to distribute pins from head of compound page to tails during
the split.

We will need ->_mapcount to account PTE mappings of subpages of the
compound page.  We eliminate need in current meaning of ->_mapcount in
tail pages by forbidding split entirely if the page is pinned.

The only user of tail page refcounting is THP which is marked BROKEN for
now.

Let's drop all this mess.  It makes get_page() and put_page() much
simpler.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
..
kasan kasan: fix kmemleak false-positive in kasan_module_alloc() 2015-11-20 16:17:32 -08:00
Kconfig mm: temporarily mark THP broken 2016-01-15 17:56:32 -08:00
Kconfig.debug mm/debug_pagealloc: remove obsolete Kconfig options 2015-01-08 15:10:52 -08:00
Makefile media updates for v4.3-rc1 2015-09-11 16:42:39 -07:00
backing-dev.c mm: memcontrol: export root_mem_cgroup 2016-01-14 16:00:49 -08:00
balloon_compaction.c mm: page migration trylock newpage at same level as oldpage 2015-11-05 19:34:48 -08:00
bootmem.c x86/mm: Introduce max_possible_pfn 2015-12-06 12:46:31 +01:00
cleancache.c cleancache: remove limit on the number of cleancache enabled filesystems 2015-04-14 16:49:03 -07:00
cma.c mm/cma.c: suppress warning 2015-11-05 19:34:48 -08:00
cma.h mm: cma: mark cma_bitmap_maxno() inline in header 2015-08-14 15:56:32 -07:00
cma_debug.c mm/cma_debug: correct size input to bitmap function 2015-07-17 16:39:54 -07:00
compaction.c mm/compaction.c: __compact_pgdat() code cleanuup 2016-01-14 16:00:49 -08:00
debug-pagealloc.c mm/debug-pagealloc: make debug-pagealloc boottime configurable 2014-12-13 12:42:48 -08:00
debug.c mm: rework virtual memory accounting 2016-01-14 16:00:49 -08:00
dmapool.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
early_ioremap.c mm/early_ioremap: use offset_in_page macro 2015-11-05 19:34:48 -08:00
fadvise.c writeback: implement and use inode_congested() 2015-06-02 08:33:35 -06:00
failslab.c mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM 2015-11-06 17:50:42 -08:00
filemap.c memcg: adjust to support new THP refcounting 2016-01-15 17:56:32 -08:00
frame_vector.c mm: fix docbook comment for get_vaddr_frames() 2015-11-05 19:34:48 -08:00
frontswap.c frontswap: allow multiple backends 2015-06-24 17:49:45 -07:00
gup.c mm: drop tail page refcounting 2016-01-15 17:56:32 -08:00
highmem.c mm/highmem: make kmap cache coloring aware 2014-08-06 18:01:22 -07:00
huge_memory.c mm: drop tail page refcounting 2016-01-15 17:56:32 -08:00
hugetlb.c mm: drop tail page refcounting 2016-01-15 17:56:32 -08:00
hugetlb_cgroup.c mm: make compound_head() robust 2015-11-06 17:50:42 -08:00
hwpoison-inject.c hwpoison: use page_cgroup_ino for filtering by memcg 2015-09-10 13:29:01 -07:00
init-mm.c
internal.h mm: drop tail page refcounting 2016-01-15 17:56:32 -08:00
interval_tree.c mm: replace vma->sharead.linear with vma->shared 2015-02-10 14:30:31 -08:00
kmemcheck.c mm/slab_common: move kmem_cache definition to internal header 2014-10-09 22:25:50 -04:00
kmemleak-test.c mm/kmemleak-test.c: use pr_fmt for logging 2014-06-06 16:08:18 -07:00
kmemleak.c Revert "gfp: add __GFP_NOACCOUNT" 2016-01-14 16:00:49 -08:00
ksm.c rmap: add argument to charge compound page 2016-01-15 17:56:32 -08:00
list_lru.c memcg: simplify and inline __mem_cgroup_from_kmem 2015-11-05 19:34:48 -08:00
maccess.c mm/maccess.c: actually return -EFAULT from strncpy_from_unsafe 2015-11-05 19:34:48 -08:00
madvise.c mm: madvise allow remove operation for hugetlbfs 2015-09-08 15:35:28 -07:00
memblock.c mm/memblock: introduce for_each_memblock_type() 2016-01-14 16:00:49 -08:00
memcontrol.c memcg: adjust to support new THP refcounting 2016-01-15 17:56:32 -08:00
memory-failure.c page-flags: define PG_locked behavior on compound pages 2016-01-15 17:56:32 -08:00
memory.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
memory_hotplug.c memory-hotplug: don't BUG() in register_memory_resource() 2016-01-14 16:00:49 -08:00
mempolicy.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
mempool.c mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd 2015-11-06 17:50:42 -08:00
memtest.c memtest: remove unused header files 2015-09-08 15:35:28 -07:00
migrate.c rmap: add argument to charge compound page 2016-01-15 17:56:32 -08:00
mincore.c mm/mincore: use offset_in_page macro 2015-11-05 19:34:48 -08:00
mlock.c thp, mlock: do not allow huge pages in mlocked area 2016-01-15 17:56:32 -08:00
mm_init.c mm: meminit: remove mminit_verify_page_links 2015-06-30 19:44:56 -07:00
mmap.c mm: rework virtual memory accounting 2016-01-14 16:00:49 -08:00
mmu_context.c sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm 2014-02-21 08:50:17 +01:00
mmu_notifier.c mmu-notifier: add clear_young callback 2015-09-10 13:29:01 -07:00
mmzone.c mm/mmzone.c: memmap_valid_within() can be boolean 2016-01-14 16:00:49 -08:00
mprotect.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
mremap.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
msync.c mm/msync: use offset_in_page macro 2015-11-05 19:34:48 -08:00
nobootmem.c x86/mm: Introduce max_possible_pfn 2015-12-06 12:46:31 +01:00
nommu.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
oom_kill.c mm, shmem: add internal shmem resident memory accounting 2016-01-14 16:00:49 -08:00
page-writeback.c mm: page_alloc: generalize the dirty balance reserve 2016-01-14 16:00:49 -08:00
page_alloc.c mm: sanitize page->mapping for tail pages 2016-01-15 17:56:32 -08:00
page_counter.c mm: page_counter: let page_counter_try_charge() return bool 2015-11-05 19:34:48 -08:00
page_ext.c mm: introduce idle page tracking 2015-09-10 13:29:01 -07:00
page_idle.c mm: introduce idle page tracking 2015-09-10 13:29:01 -07:00
page_io.c fs: use helper bio_add_page() instead of open coding on bi_io_vec 2015-08-13 12:32:00 -06:00
page_isolation.c mm/page_isolation: use macro to judge the alignment 2016-01-14 16:00:49 -08:00
page_owner.c mm/page_owner: set correct gfp_mask on page_owner 2015-07-17 16:39:54 -07:00
pagewalk.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
percpu-km.c percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated 2014-09-02 14:46:05 -04:00
percpu-vm.c percpu: move region iterations out of pcpu_[de]populate_chunk() 2014-09-02 14:46:02 -04:00
percpu.c mm/percpu: use offset_in_page macro 2015-11-05 19:34:48 -08:00
pgtable-generic.c mm, thp: use list_first_entry_or_null() 2016-01-14 16:00:49 -08:00
process_vm_access.c process_vm_access: switch to {compat_,}import_iovec() 2015-04-11 22:27:12 -04:00
quicklist.c
readahead.c mm: move lru_to_page to mm_inline.h 2016-01-14 16:00:49 -08:00
rmap.c rmap: add argument to charge compound page 2016-01-15 17:56:32 -08:00
shmem.c memcg: adjust to support new THP refcounting 2016-01-15 17:56:32 -08:00
slab.c mm/slab.c: add a helper function get_first_slab 2016-01-14 16:00:49 -08:00
slab.h slab: add SLAB_ACCOUNT flag 2016-01-14 16:00:49 -08:00
slab_common.c slab: add SLAB_ACCOUNT flag 2016-01-14 16:00:49 -08:00
slob.c slab/slub: adjust kmem_cache_alloc_bulk API 2015-11-22 11:58:44 -08:00
slub.c page-flags: define PG_locked behavior on compound pages 2016-01-15 17:56:32 -08:00
sparse-vmemmap.c mm/sparse: use memblock apis for early memory allocations 2014-01-21 16:19:47 -08:00
sparse.c mm: use macros from compiler.h instead of __attribute__((...)) 2014-04-07 16:35:54 -07:00
swap.c mm: drop tail page refcounting 2016-01-15 17:56:32 -08:00
swap_cgroup.c mm: page_cgroup: rename file to mm/swap_cgroup.c 2014-12-10 17:41:09 -08:00
swap_state.c page-flags: define PG_locked behavior on compound pages 2016-01-15 17:56:32 -08:00
swapfile.c mm, thp: adjust conditions when we can reuse the page on WP fault 2016-01-15 17:56:32 -08:00
truncate.c memcg: add per cgroup dirty page accounting 2015-06-02 08:33:33 -06:00
userfaultfd.c memcg: adjust to support new THP refcounting 2016-01-15 17:56:32 -08:00
util.c mm: sanitize page->mapping for tail pages 2016-01-15 17:56:32 -08:00
vmacache.c mm/vmacache: inline vmacache_valid_mm() 2015-11-05 19:34:48 -08:00
vmalloc.c mm, vmalloc: remove VM_VPAGES 2016-01-14 16:00:49 -08:00
vmpressure.c memcg: avoid vmpressure oops when memcg disabled 2016-01-14 16:00:49 -08:00
vmscan.c page-flags: define PG_locked behavior on compound pages 2016-01-15 17:56:32 -08:00
vmstat.c mm, vmstats: new THP splitting event 2016-01-15 17:56:32 -08:00
workingset.c list_lru: add helpers to isolate items 2015-02-12 18:54:10 -08:00
zbud.c mm/zbud.c: use list_last_entry() instead of list_tail_entry() 2016-01-15 11:40:52 -08:00
zpool.c mm: zsmalloc: constify struct zs_pool name 2015-11-06 17:50:42 -08:00
zsmalloc.c zsmalloc: reorganize struct size_class to pack 4 bytes hole 2016-01-15 11:40:52 -08:00
zswap.c mm/zswap: change incorrect strncmp use to strcmp 2015-12-18 14:25:40 -08:00