From mboxrd@z Thu Jan 1 00:00:00 1970 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 3D18933A701; Sun, 1 Mar 2026 17:43:33 +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=1772387013; cv=none; b=sadSp2X0yjF72NJZEkUUJH9niiBuBCgYsLjP0ycvBSVFA+seuvPck1E5umslmkBLdPGl62ir8zHZGqPiWW3wMyKhiESYv2agTXhsg6D2X0O3Yv4Vnd/SLEqfKYolmCkfaZ3qoaXNtGsv3dXhX245FbLhtRAEOvXV34wlT4un3Pc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772387013; c=relaxed/simple; bh=7QL/RYpMYPTB1eC/p0ZRS1BwtD3YKWYXznWIGxGADnA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gOWOdtZQT4JwuwnPwSCnIIdQNGcuQ42Ij4UXVYzuaemLIw8oYUvLe8rwane/c3i9ugGr56zTc19Xs8les7CCORGCPnyCxcO9byC6P9xFwii4D5Y85aWmDok+2xO24IuX5rOnuQHKEBJSsv1mbfOXNIsdR/mBLZg73w8/oLq3x94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R7kM60CE; 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="R7kM60CE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0281DC2BC86; Sun, 1 Mar 2026 17:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772387013; bh=7QL/RYpMYPTB1eC/p0ZRS1BwtD3YKWYXznWIGxGADnA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R7kM60CEmDaEzNJTLTipUMV58oimjOz6LLzz56XC7mxaW9NAFTZrX1ECyv31z3LXx 47QuYTMJoYczO1ndrolzeKIUlFl5c7SpKgDLHOpUdGVDfNudPok6f6Pll/t/j5V5Vl Vhj50I5tC1d4Ph1ByHi5QzSbBI4I67LFXQ5/yTCee35voA5bJIynLeJ091CjVU8DZ4 +pQEWpJ4115VEYgzKJiSf9O1oFwdMSyIXtoPLpYWIiYawScj8l0SOJaZbvVmxJWQKL 4rMRRDxAzOtSWOmJDHNvSdLVkMtMRRdPoQhh/PMuJzNED+Q9286s2vTCNVnWvOAfrO NGGRBLLU8Ju/w== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v2 08/10] mm/damon/core: add damon_reset_aggregated() debug_sanity check Date: Sun, 1 Mar 2026 09:43:23 -0800 Message-ID: <20260301174327.76849-9-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260301174327.76849-1-sj@kernel.org> References: <20260301174327.76849-1-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: 8bit At time of damon_reset_aggregated(), aggregation of the interval should be completed, and hence nr_accesses and nr_accesses_bp should match. I found a few bugs caused it to be broken in the past, from online parameters update and complicated nr_accesses handling changes. Add a sanity check for that under CONFIG_DAMON_DEBUG_SANITY. Signed-off-by: SeongJae Park --- mm/damon/core.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/mm/damon/core.c b/mm/damon/core.c index be2300cf3aeae..e8c44541754f7 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1666,6 +1666,23 @@ static void damon_warn_fix_nr_accesses_corruption(struct damon_region *r) r->nr_accesses_bp = r->nr_accesses * 10000; } +#ifdef CONFIG_DAMON_DEBUG_SANITY +static void damon_verify_reset_aggregated(struct damon_region *r, + struct damon_ctx *c) +{ + WARN_ONCE(r->nr_accesses_bp != r->last_nr_accesses * 10000, + "nr_accesses_bp %u last_nr_accesses %u sis %lu %lu\n", + r->nr_accesses_bp, r->last_nr_accesses, + c->passed_sample_intervals, c->next_aggregation_sis); +} +#else +static void damon_verify_reset_aggregated(struct damon_region *r, + struct damon_ctx *c) +{ +} +#endif + + /* * Reset the aggregated monitoring results ('nr_accesses' of each region). */ @@ -1682,6 +1699,7 @@ static void kdamond_reset_aggregated(struct damon_ctx *c) damon_warn_fix_nr_accesses_corruption(r); r->last_nr_accesses = r->nr_accesses; r->nr_accesses = 0; + damon_verify_reset_aggregated(r, c); } ti++; } -- 2.47.3