From: Rik van Riel <riel@xxxxxxxxxx>
When a task is already running on its preferred node, increment
numa_migrate_seq to indicate that the task is settled if migration is
temporarily disabled, and memory should migrate towards it.
[mgorman@xxxxxxx: Only increment migrate_seq if migration temporarily disabled]
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
---
kernel/sched/fair.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 559175b..9a2e68e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1016,8 +1016,16 @@ static void numa_migrate_preferred(struct task_struct *p)
{
/* Success if task is already running on preferred CPU */
p->numa_migrate_retry = 0;
- if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid)
+ if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid) {
+ /*
+ * If migration is temporarily disabled due to a task migration
+ * then re-enable it now as the task is running on its
+ * preferred node and memory should migrate locally
+ */
+ if (!p->numa_migrate_seq)
+ p->numa_migrate_seq++;
return;
+ }
/* This task has no NUMA fault statistics yet */
if (unlikely(p->numa_preferred_nid == -1))
--
1.8.4
--
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