From 8d303e44e99c2ae5cad31f3dded10a572b0fd4d7 Mon Sep 17 00:00:00 2001 From: Piotr Kwapulinski Date: Mon, 12 Dec 2016 16:42:49 -0800 Subject: [PATCH] mm/mempolicy.c: forbid static or relative flags for local NUMA mode 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 or mbind. Return the "invalid argument" from set_mempolicy and mbind whenever any of these flags is passed along with MPOL_LOCAL. It is consistent with MPOL_PREFERRED passed with empty nodemask. It 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. Link: http://lkml.kernel.org/r/20161027163037.4089-1-kwapulinski.piotr@gmail.com Signed-off-by: Piotr Kwapulinski Acked-by: David Rientjes Cc: Kirill A. Shutemov Cc: Vlastimil Babka Cc: Michal Hocko Cc: Liang Chen Cc: Mel Gorman Cc: Dave Hansen Cc: Nathan Zimmer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 4d58021dba34..6d3639e1f254 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)) -- 2.20.1