Commit 2832bc19 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds

sched: numa: ksm: fix oops in task_numa_placment()

task_numa_placement() oopsed on NULL p->mm when task_numa_fault() got
called in the handling of break_ksm() for ksmd.  That might be a
peculiar case, which perhaps KSM could takes steps to avoid? but it's
more robust if task_numa_placement() allows for such a possibility.
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cda73a10
......@@ -793,8 +793,11 @@ unsigned int sysctl_numa_balancing_scan_delay = 1000;
static void task_numa_placement(struct task_struct *p)
{
int seq = ACCESS_ONCE(p->mm->numa_scan_seq);
int seq;
if (!p->mm) /* for example, ksmd faulting in a user's mm */
return;
seq = ACCESS_ONCE(p->mm->numa_scan_seq);
if (p->numa_scan_seq == seq)
return;
p->numa_scan_seq = seq;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment