From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755802Ab3BFPt4 (ORCPT ); Wed, 6 Feb 2013 10:49:56 -0500 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:41530 "EHLO e06smtp12.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753843Ab3BFPtz (ORCPT ); Wed, 6 Feb 2013 10:49:55 -0500 From: Gerald Schaefer To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Vivek Goyal , Hugh Dickins , David Rientjes , Mel Gorman , Martin Schwidefsky , Heiko Carstens , Gerald Schaefer Subject: [PATCH] mm: don't overwrite mm->def_flags in do_mlockall() Date: Wed, 6 Feb 2013 16:49:34 +0100 Message-Id: <1360165774-55458-1-git-send-email-gerald.schaefer@de.ibm.com> X-Mailer: git-send-email 1.7.12.4 x-cbid: 13020615-8372-0000-0000-00000518DB6E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With commit 8e72033 "thp: make MADV_HUGEPAGE check for mm->def_flags" the VM_NOHUGEPAGE flag may be set on s390 in mm->def_flags for certain processes, to prevent future thp mappings. This would be overwritten by do_mlockall(), which sets it back to 0 with an optional VM_LOCKED flag set. To fix this, instead of overwriting mm->def_flags in do_mlockall(), only the VM_LOCKED flag should be set or cleared. Reported-by: Vivek Goyal Signed-off-by: Gerald Schaefer --- mm/mlock.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/mlock.c b/mm/mlock.c index f0b9ce5..c9bd528 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -517,11 +517,11 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) static int do_mlockall(int flags) { struct vm_area_struct * vma, * prev = NULL; - unsigned int def_flags = 0; if (flags & MCL_FUTURE) - def_flags = VM_LOCKED; - current->mm->def_flags = def_flags; + current->mm->def_flags |= VM_LOCKED; + else + current->mm->def_flags &= ~VM_LOCKED; if (flags == MCL_FUTURE) goto out; -- 1.7.12.4