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authorMel Gorman <mgorman@suse.de>2014-01-22 03:51:01 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-22 04:19:48 +0400
commitaf1839d722c986ffeaae1e70a6ef1c75ff38dcd5 (patch)
tree9de959141096c28bbb9ff65ffe8e087f88df231d
parent1c5e9c27cbd966c7f0038698d5dcd5ada3574f47 (diff)
downloadlinux-af1839d722c986ffeaae1e70a6ef1c75ff38dcd5.tar.xz
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>
-rw-r--r--include/trace/events/migrate.h26
-rw-r--r--mm/migrate.c5
2 files changed, 30 insertions, 1 deletions
diff --git a/include/trace/events/migrate.h b/include/trace/events/migrate.h
index ec2a6ccfd7e5..3075ffbb9a83 100644
--- a/include/trace/events/migrate.h
+++ b/include/trace/events/migrate.h
@@ -45,6 +45,32 @@ TRACE_EVENT(mm_migrate_pages,
__print_symbolic(__entry->reason, MIGRATE_REASON))
);
+TRACE_EVENT(mm_numa_migrate_ratelimit,
+
+ TP_PROTO(struct task_struct *p, int dst_nid, unsigned long nr_pages),
+
+ TP_ARGS(p, dst_nid, nr_pages),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN)
+ __field( pid_t, pid)
+ __field( int, dst_nid)
+ __field( unsigned long, nr_pages)
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, p->comm, TASK_COMM_LEN);
+ __entry->pid = p->pid;
+ __entry->dst_nid = dst_nid;
+ __entry->nr_pages = nr_pages;
+ ),
+
+ TP_printk("comm=%s pid=%d dst_nid=%d nr_pages=%lu",
+ __entry->comm,
+ __entry->pid,
+ __entry->dst_nid,
+ __entry->nr_pages)
+);
#endif /* _TRACE_MIGRATE_H */
/* This part must be outside protection */
diff --git a/mm/migrate.c b/mm/migrate.c
index 4612bb2e3677..f9e16350d09c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -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.