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author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2018-08-23 17:00:42 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-23 18:48:43 -0700 |
commit | d4ae9916ea2947341180d2b538f48875ff393a86 (patch) | |
tree | e478e5e6e84de25fade8f2995c9ee49cacd5a488 /include | |
parent | 6bc9b56433b76e40d11099338d27fbc5cd2935ca (diff) | |
download | linux-d4ae9916ea2947341180d2b538f48875ff393a86.tar.bz2 |
mm: soft-offline: close the race against page allocation
A process can be killed with SIGBUS(BUS_MCEERR_AR) when it tries to
allocate a page that was just freed on the way of soft-offline. This is
undesirable because soft-offline (which is about corrected error) is
less aggressive than hard-offline (which is about uncorrected error),
and we can make soft-offline fail and keep using the page for good
reason like "system is busy."
Two main changes of this patch are:
- setting migrate type of the target page to MIGRATE_ISOLATE. As done
in free_unref_page_commit(), this makes kernel bypass pcplist when
freeing the page. So we can assume that the page is in freelist just
after put_page() returns,
- setting PG_hwpoison on free page under zone->lock which protects
freelists, so this allows us to avoid setting PG_hwpoison on a page
that is decided to be allocated soon.
[akpm@linux-foundation.org: tweak set_hwpoison_free_buddy_page() comment]
Link: http://lkml.kernel.org/r/1531452366-11661-3-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zy.zhengyi@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/page-flags.h | 5 | ||||
-rw-r--r-- | include/linux/swapops.h | 10 |
2 files changed, 5 insertions, 10 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 901943e4754b..74bee8cecf4c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -369,8 +369,13 @@ PAGEFLAG_FALSE(Uncached) PAGEFLAG(HWPoison, hwpoison, PF_ANY) TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) +extern bool set_hwpoison_free_buddy_page(struct page *page); #else PAGEFLAG_FALSE(HWPoison) +static inline bool set_hwpoison_free_buddy_page(struct page *page) +{ + return 0; +} #define __PG_HWPOISON 0 #endif diff --git a/include/linux/swapops.h b/include/linux/swapops.h index 1d3877c39a00..568a3553d918 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -340,11 +340,6 @@ static inline int is_hwpoison_entry(swp_entry_t entry) return swp_type(entry) == SWP_HWPOISON; } -static inline bool test_set_page_hwpoison(struct page *page) -{ - return TestSetPageHWPoison(page); -} - static inline void num_poisoned_pages_inc(void) { atomic_long_inc(&num_poisoned_pages); @@ -367,11 +362,6 @@ static inline int is_hwpoison_entry(swp_entry_t swp) return 0; } -static inline bool test_set_page_hwpoison(struct page *page) -{ - return false; -} - static inline void num_poisoned_pages_inc(void) { } |