[PATCH 14/63] sched: numa: Continue PTE scanning even if migrate rate limited

From: Mel Gorman
Date: Fri Sep 27 2013 - 09:42:41 EST

From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

Avoiding marking PTEs pte_numa because a particular NUMA node is migrate rate
limited sees like a bad idea. Even if this node can't migrate anymore other
nodes might and we want up-to-date information to do balance decisions.
We already rate limit the actual migrations, this should leave enough
bandwidth to allow the non-migrating scanning. I think its important we
keep up-to-date information if we're going to do placement based on it.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
kernel/sched/fair.c | 8 --------
1 file changed, 8 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index db83eb1..f2580ce 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -951,14 +951,6 @@ void task_numa_work(struct callback_head *work)
p->node_stamp += 2 * TICK_NSEC;

- /*
- * Do not set pte_numa if the current running node is rate-limited.
- * This loses statistics on the fault but if we are unwilling to
- * migrate to this node, it is less likely we can do useful work
- */
- if (migrate_ratelimited(numa_node_id()))
- return;
start = mm->numa_scan_offset;
pages = sysctl_numa_balancing_scan_size;
pages <<= 20 - PAGE_SHIFT; /* MB in pages */

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/