tree a119f949799e3cd7382548eac2b41fa060c29ac5
parent 106dd5afde3cd10db7e1370b6ddc77f0b2496a75
author Rik van Riel <riel@redhat.com> 1384216165 -0500
committer Ingo Molnar <mingo@kernel.org> 1384346031 +0100

sched/numa: Fix NULL pointer dereference in task_numa_migrate()

The cpusets code can split up the scheduler's domain tree into
smaller domains.  Some of those smaller domains may not cross
NUMA nodes at all, leading to a NULL pointer dereference on the
per-cpu sd_numa pointer.

Tasks cannot be migrated out of their domain, so the patch
also sets p->numa_preferred_nid to whereever they are, to
prevent the migration from being retried over and over again.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Link: http://lkml.kernel.org/n/tip-oosqomw0Jput0Jkvoowhrqtu@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>