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 <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: Alex Thorlton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Mel Gorman 2014-01-21 15:51:01 -08:00 • committed by Linus Torvalds
commit af1839d722
2 changed files with 30 additions and 1 deletions

View file

@ -1614,8 +1614,11 @@ static bool numamigrate_update_ratelimit(pg_data_t *pgdat,
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.