mm: numa: trace tasks that fail migration due to rate limiting
A low local/remote numa hinting fault ratio is potentially explained by
failed migrations. This patch adds a tracepoint that fires when
migration fails due to migration rate limitation.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/migrate.c b/mm/migrate.c
index 4612bb2..f9e1635 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1614,8 +1614,11 @@
msecs_to_jiffies(migrate_interval_millisecs);
spin_unlock(&pgdat->numabalancing_migrate_lock);
}
- if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages)
+ if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) {
+ trace_mm_numa_migrate_ratelimit(current, pgdat->node_id,
+ nr_pages);
return true;
+ }
/*
* This is an unlocked non-atomic update so errors are possible.