https://github.com/torvalds/linux
Revision 18365225f0440d09708ad9daade2ec11275c3df9 authored by Michal Hocko on 12 May 2017, 22:46:26 UTC, committed by Linus Torvalds on 12 May 2017, 22:57:15 UTC
Laurent Dufour has noticed that hwpoinsoned pages are kept charged. In his particular case he has hit a bad_page("page still charged to cgroup") when onlining a hwpoison page. While this looks like something that shouldn't happen in the first place because onlining hwpages and returning them to the page allocator makes only little sense it shows a real problem. hwpoison pages do not get freed usually so we do not uncharge them (at least not since commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API")). Each charge pins memcg (since e8ea14cc6ead ("mm: memcontrol: take a css reference for each charged page")) as well and so the mem_cgroup and the associated state will never go away. Fix this leak by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache(). We also have to tweak uncharge_list because it cannot rely on zero ref count for these pages. [akpm@linux-foundation.org: coding-style fixes] Fixes: 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API") Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Reviewed-by: Balbir Singh <bsingharora@gmail.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tip revision: 18365225f0440d09708ad9daade2ec11275c3df9 authored by Michal Hocko on 12 May 2017, 22:46:26 UTC
hwpoison, memcg: forcibly uncharge LRU pages
hwpoison, memcg: forcibly uncharge LRU pages
Tip revision: 1836522
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arch | ||
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certs | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
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.cocciconfig | -rw-r--r-- | 59 bytes |
.get_maintainer.ignore | -rw-r--r-- | 31 bytes |
.gitattributes | -rw-r--r-- | 30 bytes |
.gitignore | -rw-r--r-- | 1.3 KB |
.mailmap | -rw-r--r-- | 8.1 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 96.2 KB |
Kbuild | -rw-r--r-- | 2.2 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 397.6 KB |
Makefile | -rw-r--r-- | 58.6 KB |
README | -rw-r--r-- | 722 bytes |
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