The patch titled
Subject: mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page
has been added to the -mm tree. Its filename is
mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch
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From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Subject: mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page
Memory error handler calls try_to_unmap() for error pages in various
states. If the error page is a mlocked page, error handling could fail
with "still referenced by 1 users" message. This is because the page
is linked to and stays in lru cache after the following call chain.
try_to_unmap_one
page_remove_rmap
clear_page_mlock
putback_lru_page
lru_cache_add
memory_failure() calls shake_page() to hanlde the similar issue, but
current code doesn't cover because shake_page() is called only before
try_to_unmap(). So this patches adds shake_page().
Fixes: 23a003bfd23ea9ea0b7756b920e51f64b284b468 ("mm/madvise: pass return code of memory_failure() to userspace")
Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop
Link: http://lkml.kernel.org/r/1493197841-23986-3-git-send-email-n-horiguchi@xxxxxxxxxxxxx
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Cc: Xiaolong Ye <xiaolong.ye@xxxxxxxxx>
Cc: Chen Gong <gong.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff -puN mm/memory-failure.c~mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page mm/memory-failure.c
--- a/mm/memory-failure.c~mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page
+++ a/mm/memory-failure.c
@@ -919,6 +919,7 @@ static bool hwpoison_user_mappings(struc
bool unmap_success;
int kill = 1, forcekill;
struct page *hpage = *hpagep;
+ bool mlocked = PageMlocked(hpage);
/*
* Here we are interested only in user-mapped pages, so skip any
@@ -983,6 +984,13 @@ static bool hwpoison_user_mappings(struc
pfn, page_mapcount(hpage));
/*
+ * try_to_unmap() might put mlocked page in lru cache, so call
+ * shake_page() again to ensure that it's flushed.
+ */
+ if (mlocked)
+ shake_page(hpage, 0);
+
+ /*
* Now that the dirty bit has been propagated to the
* struct page and all unmaps done we can decide if
* killing is needed or not. Only kill when the page
_
Patches currently in -mm which might be from n-horiguchi@xxxxxxxxxxxxx are
mm-hwpoison-call-shake_page-unconditionally.patch
mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch
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