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author | Chen Yucong <slaoub@gmail.com> | 2014-07-02 15:22:37 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-07-03 09:21:54 -0700 |
commit | 0bc1f8b0682caa39f45ce1e0228ebf43acb46111 (patch) | |
tree | b70c12a8c2a6ec6b72dcad7bbce556a67becc1d7 /mm | |
parent | b27ebf77919fdc4e7f76b1972307c30c4a3c8859 (diff) | |
download | linux-0bc1f8b0682caa39f45ce1e0228ebf43acb46111.tar.gz linux-0bc1f8b0682caa39f45ce1e0228ebf43acb46111.tar.bz2 linux-0bc1f8b0682caa39f45ce1e0228ebf43acb46111.zip |
hwpoison: fix the handling path of the victimized page frame that belong to non-LRU
Until now, the kernel has the same policy to handle victimized page
frames that belong to kernel-space(reserved/slab-subsystem) or
non-LRU(unknown page state). In other word, the result of handling
either of these victimized page frames is (IGNORED | FAILED), and the
return value of memory_failure() is -EBUSY.
This patch is to avoid that memory_failure() returns very soon due to
the "true" value of (!PageLRU(p)), and it also ensures that
action_result() can report more precise information("reserved kernel",
"kernel slab", and "unknown page state") instead of "non LRU",
especially for memory errors which are detected by memory-scrubbing.
Andi said:
: While running the mcelog test suite on 3.14 I hit the following VM_BUG_ON:
:
: soft_offline: 0x56d4: unknown non LRU page type 3ffff800008000
: page:ffffea000015b400 count:3 mapcount:2097169 mapping: (null) index:0xffff8800056d7000
: page flags: 0x3ffff800004081(locked|slab|head)
: ------------[ cut here ]------------
: kernel BUG at mm/rmap.c:1495!
:
: I think what happened is that a LRU page turned into a slab page in
: parallel with offlining. memory_failure initially tests for this case,
: but doesn't retest later after the page has been locked.
:
: ...
:
: I ran this patch in a loop over night with some stress plus
: the mcelog test suite running in a loop. I cannot guarantee it hit it,
: but it should have given it a good beating.
:
: The kernel survived with no messages, although the mcelog test suite
: got killed at some point because it couldn't fork anymore. Probably
: some unrelated problem.
:
: So the patch is ok for me for .16.
Signed-off-by: Chen Yucong <slaoub@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memory-failure.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index cd8989c1027e..c6399e328931 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -895,7 +895,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, struct page *hpage = *hpagep; struct page *ppage; - if (PageReserved(p) || PageSlab(p)) + if (PageReserved(p) || PageSlab(p) || !PageLRU(p)) return SWAP_SUCCESS; /* @@ -1159,9 +1159,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags) action_result(pfn, "free buddy, 2nd try", DELAYED); return 0; } - action_result(pfn, "non LRU", IGNORED); - put_page(p); - return -EBUSY; } } @@ -1194,6 +1191,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags) return 0; } + if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p)) + goto identify_page_state; + /* * For error on the tail page, we should set PG_hwpoison * on the head page to show that the hugepage is hwpoisoned @@ -1243,6 +1243,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags) goto out; } +identify_page_state: res = -EBUSY; /* * The first check uses the current page flags which may not have any |