b9c565d5a2
Remove clear_page_cgroup: it's an unhelpful helper, see for example how mem_cgroup_uncharge_page had to unlock_page_cgroup just in order to call it (serious races from that? I'm not sure). Once that's gone, you can see it's pointless for page_cgroup's ref_cnt to be atomic: it's always manipulated under lock_page_cgroup, except where force_empty unilaterally reset it to 0 (and how does uncharge's atomic_dec_and_test protect against that?). Simplify this page_cgroup locking: if you've got the lock and the pc is attached, then the ref_cnt must be positive: VM_BUG_ONs to check that, and to check that pc->page matches page (we're on the way to finding why sometimes it doesn't, but this patch doesn't fix that). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: David Rientjes <rientjes@google.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hirokazu Takahashi <taka@valinux.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
allocpercpu.c | ||
backing-dev.c | ||
bootmem.c | ||
bounce.c | ||
dmapool.c | ||
fadvise.c | ||
filemap.c | ||
filemap_xip.c | ||
fremap.c | ||
highmem.c | ||
hugetlb.c | ||
internal.h | ||
Kconfig | ||
madvise.c | ||
Makefile | ||
memcontrol.c | ||
memory.c | ||
memory_hotplug.c | ||
mempolicy.c | ||
mempool.c | ||
migrate.c | ||
mincore.c | ||
mlock.c | ||
mmap.c | ||
mmzone.c | ||
mprotect.c | ||
mremap.c | ||
msync.c | ||
nommu.c | ||
oom_kill.c | ||
page-writeback.c | ||
page_alloc.c | ||
page_io.c | ||
page_isolation.c | ||
pagewalk.c | ||
pdflush.c | ||
prio_tree.c | ||
quicklist.c | ||
readahead.c | ||
rmap.c | ||
shmem.c | ||
shmem_acl.c | ||
slab.c | ||
slob.c | ||
slub.c | ||
sparse-vmemmap.c | ||
sparse.c | ||
swap.c | ||
swap_state.c | ||
swapfile.c | ||
thrash.c | ||
tiny-shmem.c | ||
truncate.c | ||
util.c | ||
vmalloc.c | ||
vmscan.c | ||
vmstat.c |