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 <[email protected]>
Signed-off-by: Rik van Riel <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Mel Gorman <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions