Re: [PATCH 12/12] mm/damon/core: add trace point for damos stat per apply interval

On Wed, 17 Dec 2025 17:48:51 -0500 Steven Rostedt [off-list ref] wrote:

On Tue, 16 Dec 2025 00:01:25 -0800
SeongJae Park [off-list ref] wrote:

quoted

+	TP_printk("ctx_idx=%u scheme_idx=%u nr_tried=%lu sz_tried=%lu "
+			"nr_applied=%lu sz_tried=%lu sz_ops_filter_passed=%lu "
+			"qt_exceeds=%lu nr_snapshots=%lu",

Nit, but it's been stated that strings should not be broken up because of
the column limit.

I also found checkpatch.pl shows warning for that.  I was ignoring that since I
was thinking that's just a recommendation.  But as I got more than one warning,
now I'd like to fix this.

Andrew, could you please add below attaching fixup patch?

quoted

+			__entry->context_idx, __entry->scheme_idx,
+			__entry->nr_tried, __entry->sz_tried,
+			__entry->nr_applied, __entry->sz_applied,
+			__entry->sz_ops_filter_passed, __entry->qt_exceeds,
+			__entry->nr_snapshots)
+);
+
 TRACE_EVENT(damos_esz,
 
 	TP_PROTO(unsigned int context_idx, unsigned int scheme_idx,

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 8908aec6670f..68dd2f7acba2 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c

@@ -2256,6 +2256,22 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s)
 	quota->min_score = score;
 }
 
+static void damos_trace_stat(struct damon_ctx *c, struct damos *s)
+{
+	unsigned int cidx = 0, sidx = 0;
+	struct damos *siter;
+
+	if (!trace_damos_stat_after_apply_interval_enabled())
+		return;

Other than that, from a tracing POV:

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Thank you! :)


Thanks,
SJ

[...]

=== >8 ===
From 67a7762ee1ade258c53913ea4ecf9bafd4746ea9 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@kernel.org>
Date: Wed, 17 Dec 2025 15:42:06 -0800
Subject: [PATCH] mm/damon: do not break the string for damos_stat tracepoint

The format string for damos_stat tracepoint is broken up to multiple
lines.  Strings shouldn't be broken up due to the column limit, though.
Update the string to be put on a single line.

Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/trace/events/damon.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h
index 24fc402ab3c8..bf25ee07cb48 100644
--- a/include/trace/events/damon.h
+++ b/include/trace/events/damon.h

@@ -40,9 +40,7 @@ TRACE_EVENT(damos_stat_after_apply_interval,
 		__entry->nr_snapshots = stat->nr_snapshots;
 	),
 
-	TP_printk("ctx_idx=%u scheme_idx=%u nr_tried=%lu sz_tried=%lu "
-			"nr_applied=%lu sz_tried=%lu sz_ops_filter_passed=%lu "
-			"qt_exceeds=%lu nr_snapshots=%lu",
+	TP_printk("ctx_idx=%u scheme_idx=%u nr_tried=%lu sz_tried=%lu nr_applied=%lu sz_tried=%lu sz_ops_filter_passed=%lu qt_exceeds=%lu nr_snapshots=%lu",
 			__entry->context_idx, __entry->scheme_idx,
 			__entry->nr_tried, __entry->sz_tried,
 			__entry->nr_applied, __entry->sz_applied,

-- 
2.47.3