From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765229AbcIRLad (ORCPT ); Sun, 18 Sep 2016 07:30:33 -0400 Received: from mail-lf0-f66.google.com ([209.85.215.66]:35917 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755520AbcIRLaX (ORCPT ); Sun, 18 Sep 2016 07:30:23 -0400 From: Piotr Kwapulinski To: akpm@linux-foundation.org Cc: kirill.shutemov@linux.intel.com, vbabka@suse.cz, rientjes@google.com, mhocko@kernel.org, mgorman@techsingularity.net, liangchen.linux@gmail.com, nzimmer@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kwapulinski.piotr@gmail.com Subject: [PATCH] mm/mempolicy.c: forbid static or relative flags for local NUMA mode Date: Sun, 18 Sep 2016 13:29:43 +0200 Message-Id: <20160918112943.1645-1-kwapulinski.piotr@gmail.com> X-Mailer: git-send-email 2.9.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES flags are irrelevant when setting them for MPOL_LOCAL NUMA memory policy via set_mempolicy. Return the "invalid argument" from set_mempolicy whenever any of these flags is passed along with MPOL_LOCAL. It is consistent with MPOL_PREFERRED passed with empty nodemask. It also slightly shortens the execution time in paths where these flags are used e.g. when trying to rebind the NUMA nodes for changes in cgroups cpuset mems (mpol_rebind_preferred()) or when just printing the mempolicy structure (/proc/PID/numa_maps). Isolated tests done. Signed-off-by: Piotr Kwapulinski --- mm/mempolicy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 2da72a5..27b07d1 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -276,7 +276,9 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags, return ERR_PTR(-EINVAL); } } else if (mode == MPOL_LOCAL) { - if (!nodes_empty(*nodes)) + if (!nodes_empty(*nodes) || + (flags & MPOL_F_STATIC_NODES) || + (flags & MPOL_F_RELATIVE_NODES)) return ERR_PTR(-EINVAL); mode = MPOL_PREFERRED; } else if (nodes_empty(*nodes)) -- 2.9.2