[PATCH v20 08/15] mm/damon: Add a tracepoint

From: SeongJae Park
Date: Mon Aug 17 2020 - 06:56:33 EST


From: SeongJae Park <sjpark@xxxxxxxxx>

This commit adds a tracepoint for DAMON. It traces the monitoring
results of each region for each aggregation interval. Using this, DAMON
can easily integrated with tracepoints supporting tools such as perf.

Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx>
Reviewed-by: Leonard Foerster <foersleo@xxxxxxxxx>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/trace/events/damon.h | 43 ++++++++++++++++++++++++++++++++++++
mm/damon.c | 4 ++++
2 files changed, 47 insertions(+)
create mode 100644 include/trace/events/damon.h

diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h
new file mode 100644
index 000000000000..2f422f4f1fb9
--- /dev/null
+++ b/include/trace/events/damon.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM damon
+
+#if !defined(_TRACE_DAMON_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DAMON_H
+
+#include <linux/damon.h>
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(damon_aggregated,
+
+ TP_PROTO(struct damon_target *t, struct damon_region *r,
+ unsigned int nr_regions),
+
+ TP_ARGS(t, r, nr_regions),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, target_id)
+ __field(unsigned int, nr_regions)
+ __field(unsigned long, start)
+ __field(unsigned long, end)
+ __field(unsigned int, nr_accesses)
+ ),
+
+ TP_fast_assign(
+ __entry->target_id = t->id;
+ __entry->nr_regions = nr_regions;
+ __entry->start = r->ar.start;
+ __entry->end = r->ar.end;
+ __entry->nr_accesses = r->nr_accesses;
+ ),
+
+ TP_printk("target_id=%lu nr_regions=%u %lu-%lu: %u",
+ __entry->target_id, __entry->nr_regions,
+ __entry->start, __entry->end, __entry->nr_accesses)
+);
+
+#endif /* _TRACE_DAMON_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/mm/damon.c b/mm/damon.c
index fed35f7b3879..e52e107c90fd 100644
--- a/mm/damon.c
+++ b/mm/damon.c
@@ -32,6 +32,9 @@
#include <linux/sched/task.h>
#include <linux/slab.h>

+#define CREATE_TRACE_POINTS
+#include <trace/events/damon.h>
+
/* Minimal region size. Every damon_region is aligned by this. */
#define MIN_REGION PAGE_SIZE

@@ -870,6 +873,7 @@ static void kdamond_reset_aggregated(struct damon_ctx *c)
damon_write_rbuf(c, &r->ar.end, sizeof(r->ar.end));
damon_write_rbuf(c, &r->nr_accesses,
sizeof(r->nr_accesses));
+ trace_damon_aggregated(t, r, nr);
r->nr_accesses = 0;
}
}
--
2.17.1