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 47FDF3246F8; Sat, 21 Feb 2026 19:36:36 +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=1771702597; cv=none; b=bAzmBccHVH+fiU2ndD0rKOmG9kaxtYqcnPvquOVXn+iscbRtj/5DhqT3c3zaf58sErtU+WlWwel3McFJNxQqfOM5fRFcvMhtnb93Kkn6DwFAwdxhBUBNK2aqdkpnO/1+MKTOxMt3MxfjI9WtzVN0vYGqfAZj4mtgiN1dt00Op9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771702597; c=relaxed/simple; bh=yfRhExNso4AJw0G3Gu/sbFcwdK0et66BbTZ7++AzIBc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TaMkoXJa26LF8CjNV0P22SMkylzohsL+0V15H7l1kmuSpDaV9d7QyJZk9ZEYIT8M2HoUsx5X14PX2lM9wi4QM5bRvbjtgWUs/Q77Xg7EH33BTvf1IMTPYSIJ7RpPWZBmzji2WutRD9aWD4jRN2ClnnkovI3yObtp3Mkdbp3LH2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GB4ZFNP8; 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="GB4ZFNP8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C15AC4CEF7; Sat, 21 Feb 2026 19:36:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771702596; bh=yfRhExNso4AJw0G3Gu/sbFcwdK0et66BbTZ7++AzIBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GB4ZFNP86ucw+3iCZiFXKFSKc+7g7gQXYBizUVaM6G8Pj5spY5ST9Ekt2IMMeJPSv ujn4pxCagJ8hVsjzpmdB5AZwSv+BwpeYomGyngaJVAhKPUhDJd8kO9Ki1uLpkUDxmU jgl3T2QbmIMMnMw4xG63UgEC6QJojN5Yp4J9vzqz5oR2FZuTREgMJy+sa4+Lq1V81D gBAQD03RWTC+cT/HNkoiWnHNWyY2vmsi+oSCpTobkdBgmdM+q3o3A8r/A4dYmrLOl0 rHTj1f43HloJtzgTWOzPQc/ryMrkIP9wNBcf1HzwTyMTO6Y2fbGo5LqWaGMOFuIlcJ 1ESR5NKOJQC5g== 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 07/10] mm/damon/core: add damon_split_region_at() debug_sanity check Date: Sat, 21 Feb 2026 11:36:24 -0800 Message-ID: <20260221193629.19332-8-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260221193629.19332-1-sj@kernel.org> References: <20260221193629.19332-1-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 damon_split_region_at() should be called with the correct address to split on. Add a sanity check for that under CONFIG_DAMON_DEBUG_SANITY. Signed-off-by: SeongJae Park --- mm/damon/core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/mm/damon/core.c b/mm/damon/core.c index 94be598cafef1..16f7994903d6d 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2629,6 +2629,23 @@ static void kdamond_merge_regions(struct damon_ctx *c, unsigned int threshold, threshold / 2 < max_thres); } +#ifdef CONFIG_DAMON_DEBUG_SANITY +static void damon_verify_split_region_at(struct damon_region *r, + unsigned long sz_r) +{ + if (sz_r > 0 && sz_r < damon_sz_region(r)) + return; + pr_err("damon_split_region() call with r %lu-%lu (%lu), sz_r %lu\n", + r->ar.start, r->ar.end, damon_sz_region(r), sz_r); + WARN_ONCE(); +} +#else +static void damon_verify_split_region_at(struct damon_region *r, + unsigned long sz_r) +{ +} +#endif + /* * Split a region in two * @@ -2640,6 +2657,8 @@ static void damon_split_region_at(struct damon_target *t, { struct damon_region *new; + damon_verify_split_region_at(r, sz_r); + new = damon_new_region(r->ar.start + sz_r, r->ar.end); if (!new) return; -- 2.47.3