On Thu, Jul 04, 2013 at 06:18:23PM +0530, Srikar Dronamraju wrote: > * Mel Gorman <[email protected]> [2013-07-03 15:21:38]: > > > task_numa_placement checks current->mm but after buffers for faults > > have already been uselessly allocated. Move the check earlier. > > > > [[email protected]: Identified the problem] > > Signed-off-by: Mel Gorman <[email protected]> > > --- > > kernel/sched/fair.c | 22 ++++++++++++++-------- > > 1 file changed, 14 insertions(+), 8 deletions(-) > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 336074f..3c796b0 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -870,8 +870,6 @@ static void task_numa_placement(struct task_struct *p) > > int seq, nid, max_nid = 0; > > 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; > > @@ -945,6 +943,12 @@ void task_numa_fault(int last_nid, int node, int > > pages, bool migrated) > > if (!sched_feat_numa(NUMA)) > > return; > > > > + /* for example, ksmd faulting in a user's mm */ > > + if (!p->mm) { > > + p->numa_scan_period = sysctl_numa_balancing_scan_period_max; > > Naive question: > Why are we resetting the scan_period? >
At the time I wrote it I was thinking of tick times and meant to recheck if it's necessary but then it slipped my mind. The reset is unnecessary as curr->mm is already checked. -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
