mm/vmscan: add tracepoints for node reclaim
The page alloc fast path it may perform node reclaim, which may cause a
latency spike. We should add tracepoint for this event, and also measure
the latency it causes.
So bellow two tracepoints are introduced,
mm_vmscan_node_reclaim_begin
mm_vmscan_node_reclaim_end
Link: http://lkml.kernel.org/r/1551421452-5385-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: <shaoyafang@didiglobal.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 40ff747..39912c6 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4111,6 +4111,9 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in
.reclaim_idx = gfp_zone(gfp_mask),
};
+ trace_mm_vmscan_node_reclaim_begin(pgdat->node_id, order,
+ sc.gfp_mask);
+
cond_resched();
fs_reclaim_acquire(sc.gfp_mask);
/*
@@ -4137,6 +4140,9 @@ static int __node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned in
current->flags &= ~PF_SWAPWRITE;
memalloc_noreclaim_restore(noreclaim_flag);
fs_reclaim_release(sc.gfp_mask);
+
+ trace_mm_vmscan_node_reclaim_end(sc.nr_reclaimed);
+
return sc.nr_reclaimed >= nr_pages;
}