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

SeongJae Park
2025-12-17T23:52:31Z

On Wed, 17 Dec 2025 17:48:51 -0500 Steven Rostedt <rostedt@goodmis.org> wrote:

> On Tue, 16 Dec 2025 00:01:25 -0800
> SeongJae Park <sj@kernel.org> wrote:
>
> > + 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?

>
> > + __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