sched/numa: Track NUMA hinting faults on per-node basis
This patch tracks what nodes numa hinting faults were incurred on.
This information is later used to schedule a task on the node storing
the pages most frequently faulted by the task.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-20-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c6c3302..0bb3e0a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -902,7 +902,14 @@
if (!numabalancing_enabled)
return;
- /* FIXME: Allocate task-specific structure for placement policy here */
+ /* Allocate buffer to track faults on a per-node basis */
+ if (unlikely(!p->numa_faults)) {
+ int size = sizeof(*p->numa_faults) * nr_node_ids;
+
+ p->numa_faults = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
+ if (!p->numa_faults)
+ return;
+ }
/*
* If pages are properly placed (did not migrate) then scan slower.
@@ -918,6 +925,8 @@
}
task_numa_placement(p);
+
+ p->numa_faults[node] += pages;
}
static void reset_ptenuma_scan(struct task_struct *p)