From: Mel Gorman Date: Mon, 7 Oct 2013 10:29:04 +0000 (+0100) Subject: sched/numa: Check current->mm before allocating NUMA faults X-Git-Tag: upstream/snapshot3+hdmi~4037^2~64 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9ff1d9ff3c2c8ab3feaeb2e8056a07ca293f7bde;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git sched/numa: Check current->mm before allocating NUMA faults task_numa_placement checks current->mm but after buffers for faults have already been uselessly allocated. Move the check earlier. [peterz@infradead.org: Identified the problem] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-27-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar --- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 89eeb89..3383079 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -930,8 +930,6 @@ static void task_numa_placement(struct task_struct *p) int seq, nid, max_nid = -1; unsigned long max_faults = 0; - 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; @@ -998,6 +996,10 @@ void task_numa_fault(int last_nid, int node, int pages, bool migrated) if (!numabalancing_enabled) return; + /* for example, ksmd faulting in a user's mm */ + if (!p->mm) + return; + /* For now, do not attempt to detect private/shared accesses */ priv = 1;