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 7044622D79F for ; Wed, 21 May 2025 16:57:30 +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=1747846650; cv=none; b=fH5qsOcgqu8HbXcaY37p1rpToPC8dE4CZi+EbQ0kNKJVibh3zszOR/bhkA1iFKaOY3GVk0AWMxV4ucIMOO72a7WKF/MRNzRlwp4M81vhxL5ibcUTPvATqwGO8Scw4VETXfBBOVAsudCqGp2NE5rGcN2Ikx+wsNSJS3MxFM9UotY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747846650; c=relaxed/simple; bh=kvUsNqOrk85Tv6XQ6JTgHMqL7JmwKMfekZkUjIzRVkE=; h=Date:To:From:Subject:Message-Id; b=I3/VUNQ+983DjyqpRSEiEEkpVQW6aw4j/Nu4Vjk3GUMsMPvg3bE6kZWp83yYveozTE2f+pMBZOkyzmOlvVJhsF8+bQlRaXg9KozyUI/RyCnQ+0uOrzlB3z/eu7OfMUUUGht66CnZ42HunOkOjNxxBPVB/0MP7bL2onbqSCVMhqo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Oz88zSqv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Oz88zSqv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC270C4CEE4; Wed, 21 May 2025 16:57:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747846649; bh=kvUsNqOrk85Tv6XQ6JTgHMqL7JmwKMfekZkUjIzRVkE=; h=Date:To:From:Subject:From; b=Oz88zSqv3edGdmTmPlccaEEgPy0SpAYwXmdoZBiYup7M4fFQvIUuffhLkwgan/BpE AxmZVRKCLXlKsJHA0WMkRU1whBEHZXaR5Gfq88gf0NmpFUzy4D2p3BWDNkMHB1GeF0 0jrnwPi/FHVi+TfbuN9vZnHoXAkIGp6AhNuzqxrk= Date: Wed, 21 May 2025 09:57:29 -0700 To: mm-commits@vger.kernel.org,shuah@kernel.org,davidgow@google.com,corbet@lwn.net,brendan.higgins@linux.dev,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-damon-core-warn-and-fix-nr_accesses-corruption.patch removed from -mm tree Message-Id: <20250521165729.CC270C4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/damon/core: warn and fix nr_accesses[_bp] corruption has been removed from the -mm tree. Its filename was mm-damon-core-warn-and-fix-nr_accesses-corruption.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: SeongJae Park Subject: mm/damon/core: warn and fix nr_accesses[_bp] corruption Date: Mon, 12 May 2025 17:27:10 -0700 Patch series "mm/damon: minor fixups and improvements for code, tests, and documents". Yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. This patch (of 6): For a bug such as double aggregation reset[1], ->nr_accesses and/or ->nr_accesses_bp of damon_region could be corrupted. Such corruption can make monitoring results pretty inaccurate, so the root causing bug should be investigated. Meanwhile, the corruption itself can easily be fixed but silently fixing it will hide the bug. Fix the corruption as soon as found, but WARN_ONCE() so that we can be aware of the existence of the bug while keeping the system running in a more sane way. Link: https://lkml.kernel.org/r/20250513002715.40126-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250513002715.40126-2-sj@kernel.org Link: https://lore.kernel.org/20250302214145.356806-1-sj@kernel.org [1] Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: Jonathan Corbet Cc: Shuah Khan Signed-off-by: Andrew Morton --- mm/damon/core.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/mm/damon/core.c~mm-damon-core-warn-and-fix-nr_accesses-corruption +++ a/mm/damon/core.c @@ -1392,6 +1392,19 @@ int damos_walk(struct damon_ctx *ctx, st } /* + * Warn and fix corrupted ->nr_accesses[_bp] for investigations and preventing + * the problem being propagated. + */ +static void damon_warn_fix_nr_accesses_corruption(struct damon_region *r) +{ + if (r->nr_accesses_bp == r->nr_accesses * 10000) + return; + WARN_ONCE(true, "invalid nr_accesses_bp at reset: %u %u\n", + r->nr_accesses_bp, r->nr_accesses); + r->nr_accesses_bp = r->nr_accesses * 10000; +} + +/* * Reset the aggregated monitoring results ('nr_accesses' of each region). */ static void kdamond_reset_aggregated(struct damon_ctx *c) @@ -1404,6 +1417,7 @@ static void kdamond_reset_aggregated(str damon_for_each_region(r, t) { trace_damon_aggregated(ti, r, damon_nr_regions(t)); + damon_warn_fix_nr_accesses_corruption(r); r->last_nr_accesses = r->nr_accesses; r->nr_accesses = 0; } _ Patches currently in -mm which might be from sj@kernel.org are