tree 1f137113b14e0a66cf24a8c8a32650095f7234d9
parent 7c051267931a9be9c6620cc17b362bc6ee6dedc8
author Michal Hocko <mhocko@suse.com> 1464045951 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1464048254 -0700

ipc, shm: make shmem attach/detach wait for mmap_sem killable

shmat and shmdt rely on mmap_sem for write.  If the waiting task gets
killed by the oom killer it would block oom_reaper from asynchronous
address space reclaim and reduce the chances of timely OOM resolving.
Wait for the lock in the killable mode and return with EINTR if the task
got killed while waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>