On 03/11/2016 12:32 PM, Vlastimil Babka wrote:
On 02/29/2016 02:26 PM, Michal Hocko wrote:
From: Michal Hocko <mhocko@xxxxxxxx>
coredump_wait waits for mmap_sem for write currently which can
prevent oom_reaper to reclaim the oom victims address space
asynchronously because that requires mmap_sem for read. This might
happen if the oom victim is multi threaded and some thread(s) is
holding mmap_sem for read (e.g. page fault) and it is stuck in
the page allocator while other thread(s) reached coredump_wait
already.
This patch simply uses down_write_killable and bails out with EINTR
if the lock got interrupted by the fatal signal. do_coredump will
return right away and do_group_exit will take care to zap the whole
thread group.
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Forgot to point out typo in Subject which makes it hard to grep for mmap_sem
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