From 17b0573d77fbd547cbf1d711b90d269bdcc1efd3 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Mon, 23 May 2016 16:26:05 -0700 Subject: [PATCH] prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable PR_SET_THP_DISABLE requires 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 Acked-by: Vlastimil Babka Acked-by: Alex Thorlton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sys.c b/kernel/sys.c index cf8ba545c7d3..89d5be418157 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2246,7 +2246,8 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, case PR_SET_THP_DISABLE: if (arg3 || arg4 || arg5) return -EINVAL; - down_write(&me->mm->mmap_sem); + if (down_write_killable(&me->mm->mmap_sem)) + return -EINTR; if (arg2) me->mm->def_flags |= VM_NOHUGEPAGE; else