From nobody Tue Dec 2 01:06:08 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6F78E2DCC1B; Sun, 23 Nov 2025 18:43:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763923428; cv=none; b=Zz6OOOnhGRBn3uCN2HQTpgkG1UPXEhgQH+7SBtSnzl2Sa/h4F4CippCEaMPKOJirTV/26Jstx0VipQupTMKvK5xfi4krpPIrJZHhG/HiQvVQT1BgBRGoXZBKhFM2AAF4uQDrx1Z/4MlN0Z3GdajLNgfyEpKjUnH1PdndX7PwzdU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763923428; c=relaxed/simple; bh=mH5BWCQEqqk49CCwYmvCMx+4mPSEeoKbb/+aR5lpkFw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QXSyeGUpl6uWvLGDBuTZeeNXqeoG3F+He9eNzkFd9O3IoGxLwGkzyCh431lPlD4G7Idys2wldRuxmXfRRZ+OntATKjc7/vTs3QBZ9SPO+n2FTkFmYiIaLGiv99E3D2Mf/xPGYZHD97rf1XErkcthgHMWnBeCfMAHUXcubjzdaGI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RCsc9Fbe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RCsc9Fbe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 121B1C16AAE; Sun, 23 Nov 2025 18:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763923428; bh=mH5BWCQEqqk49CCwYmvCMx+4mPSEeoKbb/+aR5lpkFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RCsc9Fbe1dxQvC+VyC2YgBZqZFVqvkyNxSvEcCyUenkZyYkccaPZ7WjU6SagGMC+1 XAQajqhn2371cO9Ln+ersUfxExuUbX0dRhyVAOIGdLG/C6SLaA7bslob0Zagkl2Pwu +UcF7rMZ5atHuuvBPT3AUTwNw17iHfbMiPboUJ/R6Jg8o+LrOUJhzzZzc20IxzvVFB 0ptr86AsnPZ+Yhkuo4SiKXfev1eBSlyVTXquh6KPu8g6+wZbycgr/UgCdHlJT5RWFN t6kFESo9IRwFeJL/ZhxyNZ8fO3xIdjn/gQuQlz2eU3FTZBpUo0VNs5Hku4Qxx3uJk7 U2t8nm2EO9OQw== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , Masami Hiramatsu , Mathieu Desnoyers , Steven Rostedt , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [RFC PATCH 12/12] mm/damon/core: add trace point for damos stat per apply interval Date: Sun, 23 Nov 2025 10:43:26 -0800 Message-ID: <20251123184329.85287-13-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251123184329.85287-1-sj@kernel.org> References: <20251123184329.85287-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" DAMON users can read DAMOS stats via DAMON sysfs interface. It enables efficient, simple and flexible usages of the stats. Especially for systems not having advanced tools like perf or bpftrace, that can be useful. But if the advanced tools are available, exposing the stats via tracepoint can reduce unnecessary reimplementation of the wheels. Add a new tracepoint for DAMOS stats, namely damos_stat_after_apply_interval. The tracepoint is triggered for each scheme's apply interval and exposes the whole stat values. If the user needs sub-apply interval information for any chance, damos_before_apply tracepoint could be used. Signed-off-by: SeongJae Park --- include/trace/events/damon.h | 41 ++++++++++++++++++++++++++++++++++++ mm/damon/core.c | 15 +++++++++++++ 2 files changed, 56 insertions(+) diff --git a/include/trace/events/damon.h b/include/trace/events/damon.h index 852d725afea2..24fc402ab3c8 100644 --- a/include/trace/events/damon.h +++ b/include/trace/events/damon.h @@ -9,6 +9,47 @@ #include #include =20 +TRACE_EVENT(damos_stat_after_apply_interval, + + TP_PROTO(unsigned int context_idx, unsigned int scheme_idx, + struct damos_stat *stat), + + TP_ARGS(context_idx, scheme_idx, stat), + + TP_STRUCT__entry( + __field(unsigned int, context_idx) + __field(unsigned int, scheme_idx) + __field(unsigned long, nr_tried) + __field(unsigned long, sz_tried) + __field(unsigned long, nr_applied) + __field(unsigned long, sz_applied) + __field(unsigned long, sz_ops_filter_passed) + __field(unsigned long, qt_exceeds) + __field(unsigned long, nr_snapshots) + ), + + TP_fast_assign( + __entry->context_idx =3D context_idx; + __entry->scheme_idx =3D scheme_idx; + __entry->nr_tried =3D stat->nr_tried; + __entry->sz_tried =3D stat->sz_tried; + __entry->nr_applied =3D stat->nr_applied; + __entry->sz_applied =3D stat->sz_applied; + __entry->sz_ops_filter_passed =3D stat->sz_ops_filter_passed; + __entry->qt_exceeds =3D stat->qt_exceeds; + __entry->nr_snapshots =3D stat->nr_snapshots; + ), + + TP_printk("ctx_idx=3D%u scheme_idx=3D%u nr_tried=3D%lu sz_tried=3D%lu " + "nr_applied=3D%lu sz_tried=3D%lu sz_ops_filter_passed=3D%lu " + "qt_exceeds=3D%lu nr_snapshots=3D%lu", + __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, =20 TP_PROTO(unsigned int context_idx, unsigned int scheme_idx, diff --git a/mm/damon/core.c b/mm/damon/core.c index 36313cd1ff1c..2f212a18e4a0 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2256,6 +2256,19 @@ static void damos_adjust_quota(struct damon_ctx *c, = struct damos *s) quota->min_score =3D score; } =20 +static void damos_trace_stat(struct damon_ctx *c, struct damos *s) +{ + unsigned int cidx =3D 0, sidx =3D 0; + struct damos *siter; + + damon_for_each_scheme(siter, c) { + if (siter =3D=3D s) + break; + sidx++; + } + trace_damos_stat_after_apply_interval(cidx, sidx, &s->stat); +} + static void kdamond_apply_schemes(struct damon_ctx *c) { struct damon_target *t; @@ -2294,6 +2307,8 @@ static void kdamond_apply_schemes(struct damon_ctx *c) (s->apply_interval_us ? s->apply_interval_us : c->attrs.aggr_interval) / sample_interval; s->last_applied =3D NULL; + if (trace_damos_stat_after_apply_interval_enabled()) + damos_trace_stat(c, s); } mutex_unlock(&c->walk_control_lock); } --=20 2.47.3