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smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf04.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 96048A037B; Tue, 28 Apr 2026 18:17:32 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf04.hostedemail.com (Postfix) with ESMTPA id B6A0A20031; Tue, 28 Apr 2026 18:17:30 +0000 (UTC) Date: Tue, 28 Apr 2026 14:17:45 -0400 From: Steven Rostedt To: SeongJae Park Cc: Andrew Morton , Masami Hiramatsu , Mathieu Desnoyers , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: Re: [RFC PATCH 16/19] mm/damon: trace probe_hits Message-ID: <20260428141745.2768ac4e@gandalf.local.home> In-Reply-To: <20260426205222.93895-17-sj@kernel.org> References: <20260426205222.93895-1-sj@kernel.org> <20260426205222.93895-17-sj@kernel.org> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspamout05 X-Rspamd-Queue-Id: B6A0A20031 X-Stat-Signature: e3i1brrmasxojtp1wgmca31nxz3q5k5x X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX1/2Osv/VST2loy+Q+wM/zb0ziB5zHmuJEc= X-HE-Tag: 1777400250-143348 X-HE-Meta: U2FsdGVkX1+bOhY2GUWBxPcY0f3n9bSlRQ7NuAetINkmFXIEGE2P9gN5Ej4aestJw38OPx0baBgt/25PZZiE1VB7EyJyVdibhz94N2EKrHHHp6tuowqYE8VCZbpHEw/D0EOmMIBs4F9LubjByTQmJfZpgEBAo4NQJL+qDTomlf2ORvwaj7k0514hYstjvguJs4RyFO5EzIYxhv7JlyI9w70DByjAEA9oxNeEMIG3iBuxxVlP8yu++K+1gtiRHFsRN28XhBtorRFmqvQlBbm0Zr7Gr+UXH3Kc5VeMY62oeRXqhRkY8tM6U/zxDAwuGlXgJNvyApVE9pf/3HSXPetovkIPwD6fR8kx On Sun, 26 Apr 2026 13:52:17 -0700 SeongJae Park wrote: > Introduce a new tracepoint for exposing the per-region per-probe > positive sample count via tracefs. > > Signed-off-by: SeongJae Park > --- > include/trace/events/damon.h | 41 ++++++++++++++++++++++++++++++++++++ > mm/damon/core.c | 1 + > 2 files changed, 42 insertions(+) > > diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h > index 7e25f4469b81b..121d7bc3a2c27 100644 > --- a/include/trace/events/damon.h > +++ b/include/trace/events/damon.h > @@ -130,6 +130,47 @@ TRACE_EVENT(damon_monitor_intervals_tune, > TP_printk("sample_us=%lu", __entry->sample_us) > ); > > +TRACE_EVENT(damon_aggregated_v2, > + > + TP_PROTO(unsigned int target_id, struct damon_region *r, > + unsigned int nr_regions), > + > + TP_ARGS(target_id, r, nr_regions), > + > + TP_STRUCT__entry( > + __field(unsigned long, target_id) > + __field(unsigned int, nr_regions) Move the nr_regions to after "end" as on 64 bit machines, this creates a 4 byte hole. -- Steve > + __field(unsigned long, start) > + __field(unsigned long, end) > + __field(unsigned int, nr_accesses) > + __field(unsigned int, age) > + __field(unsigned char, probe_hit0) > + __field(unsigned char, probe_hit1) > + __field(unsigned char, probe_hit2) > + __field(unsigned char, probe_hit3) > + ), > + > + TP_fast_assign( > + __entry->target_id = target_id; > + __entry->nr_regions = nr_regions; > + __entry->start = r->ar.start; > + __entry->end = r->ar.end; > + __entry->nr_accesses = r->nr_accesses; > + __entry->age = r->age; > + __entry->probe_hit0 = r->probe_hits[0]; > + __entry->probe_hit1 = r->probe_hits[1]; > + __entry->probe_hit2 = r->probe_hits[2]; > + __entry->probe_hit3 = r->probe_hits[3]; > + ), > + > + TP_printk("target_id=%lu nr_regions=%u %lu-%lu: %u %u %hhu %hhu %hhu %hhu", > + __entry->target_id, __entry->nr_regions, > + __entry->start, __entry->end, > + __entry->nr_accesses, __entry->age, > + __entry->probe_hit0, __entry->probe_hit1, > + __entry->probe_hit2, __entry->probe_hit3) > +); > + > TRACE_EVENT(damon_aggregated, > > TP_PROTO(unsigned int target_id, struct damon_region *r, > diff --git a/mm/damon/core.c b/mm/damon/core.c > index fe14971d72747..54834b74efef4 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -1924,6 +1924,7 @@ static void kdamond_reset_aggregated(struct damon_ctx *c) > int i; > > trace_damon_aggregated(ti, r, damon_nr_regions(t)); > + trace_damon_aggregated_v2(ti, r, damon_nr_regions(t)); > damon_warn_fix_nr_accesses_corruption(r); > r->last_nr_accesses = r->nr_accesses; > r->nr_accesses = 0;