diff options
| author | Miaohe Lin <linmiaohe@huawei.com> | 2022-03-22 22:44:21 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-22 23:57:07 +0100 |
| commit | 75ee64b3c9a9695726056e9ec527e11dbf286500 (patch) | |
| tree | f12879da0ba8fae1ef820487017cf0f3964c7caf /mm/memory-failure.c | |
| parent | mm/memory-failure.c: rework the signaling logic in kill_proc (diff) | |
| download | linux-75ee64b3c9a9695726056e9ec527e11dbf286500.tar.xz linux-75ee64b3c9a9695726056e9ec527e11dbf286500.zip | |
mm/memory-failure.c: fix race with changing page more robustly
We're only intended to deal with the non-Compound page after we split
thp in memory_failure. However, the page could have changed compound
pages due to race window. If this happens, we could retry once to
hopefully handle the page next round. Also remove unneeded orig_head.
It's always equal to the hpage. So we can use hpage directly and remove
this redundant one.
Link: https://lkml.kernel.org/r/20220218090118.1105-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory-failure.c')
| -rw-r--r-- | mm/memory-failure.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 716aebcbb0de..79a32be5e7df 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1686,7 +1686,6 @@ int memory_failure(unsigned long pfn, int flags) { struct page *p; struct page *hpage; - struct page *orig_head; struct dev_pagemap *pgmap; int res = 0; unsigned long page_flags; @@ -1732,7 +1731,7 @@ try_again: goto unlock_mutex; } - orig_head = hpage = compound_head(p); + hpage = compound_head(p); num_poisoned_pages_inc(); /* @@ -1813,10 +1812,21 @@ try_again: lock_page(p); /* - * The page could have changed compound pages during the locking. - * If this happens just bail out. + * We're only intended to deal with the non-Compound page here. + * However, the page could have changed compound pages due to + * race window. If this happens, we could try again to hopefully + * handle the page next round. */ - if (PageCompound(p) && compound_head(p) != orig_head) { + if (PageCompound(p)) { + if (retry) { + if (TestClearPageHWPoison(p)) + num_poisoned_pages_dec(); + unlock_page(p); + put_page(p); + flags &= ~MF_COUNT_INCREASED; + retry = false; + goto try_again; + } action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); res = -EBUSY; goto unlock_page; |