From nobody Thu Apr 9 20:09:14 2026 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 DF4D33D3CF8; Fri, 6 Mar 2026 15:29:23 +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=1772810963; cv=none; b=m5BOHlD8PtoG4t8J9SgapuJDZvdFkCgnqVLf9CiKoUrGqJyNm4dYzWHdAdZ+r5arJk+7fhW4o6tao5+e5B7qbmJQof/wTqGuOR+Fp59U42u2ajrKVzBf4I+qgLxLi/Ao5teUEFgnsgKnHKxpsjxLkk0fpv8AYJP2bSVbuxgP8R0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772810963; c=relaxed/simple; bh=7QL/RYpMYPTB1eC/p0ZRS1BwtD3YKWYXznWIGxGADnA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jkpxuPY1bsELlID3snZykyMenIEhcPsDLeyxsAiCDi1x0Xqnf+eUGCKlz9tZVIKWjx5Dj4aaY+nCVl7AQNm2Oeb5aXqO6Cysz9JO1zBKv5xzW3NKBjnN8gv4gyeuoC9pueltu2yC3uaArWtirXgcoLJjVTn6LlBZT+3FxMW6UMY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J1fm2DUI; 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="J1fm2DUI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC5E2C2BC86; Fri, 6 Mar 2026 15:29:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772810963; bh=7QL/RYpMYPTB1eC/p0ZRS1BwtD3YKWYXznWIGxGADnA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J1fm2DUImHlRnIE6oAsvDturwnznPySYDUcJwjnRiMZUOBbLVdOKtU0o9SxybtH3N kZvG5pVzm2eyVDZbvN9VlGRBCeh2sqgNZmagwb4439kVElZSxXquDR6a3bhNdo0zJm jCJsENfOOO98J9RHHxi9sy005TXMAtrYcS0ZsjRKAcvcBNWS63zpxEGU6otnmqPVLK 9Qg49J5iBrziw1YPJGTR1YyxFckMgFkEEZzY3ygQlWk2JaCUVpTJt/8DxJrG91jkbw /ob8qXkoKrmLTnEuhpigEung45LpNG6GhWhxu4TvBoRrcTQBUIaaFNHrNiwewgfTOg hrHbX2AQctG7A== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 08/10] mm/damon/core: add damon_reset_aggregated() debug_sanity check Date: Fri, 6 Mar 2026 07:29:11 -0800 Message-ID: <20260306152914.86303-9-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260306152914.86303-1-sj@kernel.org> References: <20260306152914.86303-1-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" 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(st= ruct damon_region *r) r->nr_accesses_bp =3D r->nr_accesses * 10000; } =20 +#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 !=3D 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 =3D r->nr_accesses; r->nr_accesses =3D 0; + damon_verify_reset_aggregated(r, c); } ti++; } --=20 2.47.3