Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752487AbcDZM5D (ORCPT ); Tue, 26 Apr 2016 08:57:03 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35128 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752375AbcDZM4s (ORCPT ); Tue, 26 Apr 2016 08:56:48 -0400 From: Michal Hocko To: , Andrew Morton Cc: LKML , Michal Hocko , Alex Thorlton , Vlastimil Babka Subject: [PATCH 14/18] prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable Date: Tue, 26 Apr 2016 14:56:21 +0200 Message-Id: <1461675385-5934-15-git-send-email-mhocko@kernel.org> X-Mailer: git-send-email 2.8.0.rc3 In-Reply-To: <1461675385-5934-1-git-send-email-mhocko@kernel.org> References: <1461675385-5934-1-git-send-email-mhocko@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1022 Lines: 31 From: Michal Hocko 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. Cc: Alex Thorlton Acked-by: Vlastimil Babka Signed-off-by: Michal Hocko --- 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 -- 2.8.0.rc3