From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4760E3403E1; Tue, 21 Jul 2026 05:29:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784611751; cv=none; b=ekjQITEOh8VlCTmAOJCgSLFsGveIjW3pgXwYFsGemP2E0vBf+rtCE3jiYLSaExV+lm1T2G8/Oms8bQizwj/4jQ7FmchvtQTAUcpTm549F1zI7b6zHE6MPIU17xK6V8hNdHG7HcaBI7efKloIiQnkKDg1noJxnjh+3dMZ9wc36qQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784611751; c=relaxed/simple; bh=Jsl4XsjolC2q22fxg/W6qtyOPVZT5V818r5o9ySmTh4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t5slbe92vw4UrC6O4u6GATnmHkvDDGA5Dn0Ew4vewb9gVlJJc+U0P0w0e8EwWNsmNhJd6W+6l0xOrtO0ST0xFWcQohnCyVLqddd/4VQwMNfNbFVSiay/dkKa9bug7OhNuOc+srbjaVJBm4nAuRvSj4zjrP+5yCf+NAqsp0d+WzA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e8CTjt72; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e8CTjt72" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 035241F000E9; Tue, 21 Jul 2026 05:29:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784611750; bh=BH34Iq02e1ZazbCpDnoF+kImwBIgT5OJqyLihxokqHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e8CTjt72VaCg+aJnSkrJ04yGIVv5AuEHKW8BjUVWAQaa2ukJaYCXIa8C/fmJyWHTd Jwa+JdE0CdNHLStEQUvHw0sR7HS+tVOSZUw/+zIBstRaNwsg5143Eiw60EwukeDGEI VN2jRsHGxdjBgd1h6wNThlfS7UcH9qurRymXq/C7AvE5PWljpHbO3eVnydY+k1TWRy Pjg/QMXHPJTZP+KZOBRLtEF+8E1JBYlxMY7D7AS8MRn+GvuH6HxfKh5mAr2sOr4Nla q3W8BSBfQyaT3eZXCRvO4I1hlzzcAu9w4AA9dNR0P3yACKN9czXx2JsIetntGV5Tqa OBcV9x9UGskYQ== From: SJ Park To: stable@vger.kernel.org Cc: damon@lists.linux.dev, SeongJae Park , Andrew Morton Subject: [PATCH 6.18.y] mm/damon/core: trace esz at first setup Date: Mon, 20 Jul 2026 22:29:01 -0700 Message-ID: <20260721052901.167162-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <2026072016-imprison-unknown-9cd4@gregkh> References: <2026072016-imprison-unknown-9cd4@gregkh> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: SeongJae Park DAMON traces effective size quota from the second update, only if a change has been made by the update. Tracing only changed updates was an intentional decision to avoid unnecessary same value tracing. Always skipping the first value is just an unintended mistake. The mistake makes the tracepoint based investigation incomplete, because the first effective size quota is never traced. It is not a big issue when the 'consist' quota tuner is used, because it keeps changing the quota in the usual setup. However, when the 'temporal' tuner is used, the quota value is not changed before the goal achievement status is completely changed. For example, if the DAMOS scheme is started with an under-achieved goal, the quota is set to the maximum value, and kept the same value until the goal is achieved. Because DAMON skips the first value, the user cannot know what effective quota the current scheme is using. Only after the goal is achieved, the effective quota is changed to zero, and traced. Unconditionally trace the initial quota value to fix this problem. Note that the 'temporal' quota tuner was introduced by commit af738a6a00c1 ("mm/damon/core: introduce DAMOS_QUOTA_GOAL_TUNER_TEMPORAL"), which was added to 7.1-rc1. But even with the 'consist' quota tuner, the tracing is unintentionally incomplete. Hence this commit marks the introduction of the trace event as the broken commit. Link: https://lore.kernel.org/20260520150311.80925-1-sj@kernel.org Fixes: a86d695193bf ("mm/damon: add trace event for effective size quota") Signed-off-by: SeongJae Park Cc: # 6.17.x Signed-off-by: Andrew Morton (cherry picked from commit 7e6cc35f5283eab81a14231a64ecd640b690c48c) Signed-off-by: SJ Park --- mm/damon/core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/damon/core.c b/mm/damon/core.c index 2b7e0ee772f32..9fb96d55d13a7 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2237,6 +2237,8 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s) if (!quota->total_charged_sz && !quota->charged_from) { quota->charged_from = jiffies; damos_set_effective_quota(quota, c); + if (trace_damos_esz_enabled()) + damos_trace_esz(c, s, quota); } /* New charge window starts */ -- 2.47.3