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 B3BE24D599E for ; Wed, 7 Oct 2026 19:35:59 +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=1791401760; cv=none; b=ka8JMVCOqgUmW/juE2yJWRPRsY+fVUWzp+5BdRk9wPtFA3wBoYOVKYpf6PmT4hq+2mCLBfax3EyHriQok5ABSHtdrwyUFUGYmQCwwk4/cu+o2JrxxcF3PLvxS5hOQ0D8z6ATlpctmzFGo2FHsfbo7INvCtCTb4PzJl/teurGfb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791401760; c=relaxed/simple; bh=r4ijabIq7U9Odda8pd+VhqNeOHnDncXFhpRR9ViLZSk=; h=Date:To:From:Subject:Message-Id; b=WDFn4vz0DvDNA9+d6rxRG7EInIn2G+HXDRodbGNyQZ2QBVpc2HXSizgsg9Iy3FehVMPSn0THb9ahtk8V3uRqo4pgshsxtyHGRL0cd/VUEMhXqw5x2FCwpKGQzW2h+5G23SsBtkAMHOAaU+eKEfVTI5TdVVrQer+QTpFOIKeEU1U= 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=iCPwFjlv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="iCPwFjlv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 209101F000FF; Wed, 7 Oct 2026 19:35:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791401759; bh=dRLfDzfUmagkKtREFs9SJf86mFC2bYhwWPknbRhsO+g=; h=Date:To:From:Subject; b=iCPwFjlvbaGHaq4Tq8c95LhZs0wnQyGVzdCt8ZGTqt4z0HKg783a4rMiA49/uxXYD jWBGmkOXFBgWQ7m+idmqVqiPejj3qT9EIzAq8tR1Dhaum090U2nNRE5+ewv6xP2FOj Ev8BajD4OKKT+XaQQJ01C55wDnsWREapSxR6x6+I= Date: Wed, 07 Oct 2026 12:35:58 -0700 To: mm-commits@vger.kernel.org,sj@kernel.org,jaeyeon.lee.dev@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-ops-common-fix-age_in_sec-overflow-on-32-bit.patch added to mm-unstable branch Message-Id: <20261007193559.209101F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/ops-common: fix age_in_sec overflow on 32-bit has been added to the -mm mm-unstable branch. Its filename is mm-damon-ops-common-fix-age_in_sec-overflow-on-32-bit.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-ops-common-fix-age_in_sec-overflow-on-32-bit.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Jaeyeon Lee Subject: mm/damon/ops-common: fix age_in_sec overflow on 32-bit Date: Mon, 5 Oct 2026 23:52:05 -0700 Patch series "mm/damon: fix a minor bug, clean code, and add a test". Patch 1 from Jaeyeon Lee fixes a minor overflow issue in DAMOS. Patch 2 from Gregory Price (Meta) cleans up the code for handling of hugetlb pages. Patch 3 from Liew Rui Yan adds a kunit test for a recently fixed bug. This patch (of 3): damon_hot_score() calculates the age of a region by multiplying r->age and the aggregation interval. On 32-bit architectures, unsigned long is 32 bits, so the multiplication overflows once the age exceeds about 4295 seconds. Then old regions are scored as if they were young. Fix it by doing the calculation in 64-bit arithmetic using div_u64(). Also make age_in_sec u64, so the result is not truncated back to 32 bits. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20261006065209.41507-1-sj@kernel.org Link: https://lore.kernel.org/20261006065209.41507-2-sj@kernel.org Link: https://lore.kernel.org/20260623011652.1354-1-sj@kernel.org [1] Fixes: 198f0f4c58b9 ("mm/damon/vaddr,paddr: support pageout prioritization") Signed-off-by: Jaeyeon Lee Signed-off-by: SJ Park Signed-off-by: Andrew Morton Reviewed-by: SJ Park Assisted-by: LLM --- mm/damon/ops-common.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/damon/ops-common.c~mm-damon-ops-common-fix-age_in_sec-overflow-on-32-bit +++ a/mm/damon/ops-common.c @@ -164,7 +164,7 @@ int damon_hot_score(struct damon_ctx *c, struct damos *s) { int freq_subscore; - unsigned int age_in_sec; + u64 age_in_sec; int age_in_log, age_subscore; unsigned int freq_weight = s->quota.weight_nr_accesses; unsigned int age_weight = s->quota.weight_age; @@ -174,7 +174,8 @@ int damon_hot_score(struct damon_ctx *c, DAMON_MAX_SUBSCORE, damon_nr_samples_per_aggr(&c->attrs)); - age_in_sec = (unsigned long)r->age * c->attrs.aggr_interval / 1000000; + age_in_sec = div_u64((u64)r->age * c->attrs.aggr_interval, + USEC_PER_SEC); if (age_in_sec) age_in_log = min_t(int, ilog2(age_in_sec) + 1, DAMON_MAX_AGE_IN_LOG); _ Patches currently in -mm which might be from jaeyeon.lee.dev@gmail.com are selftests-mm-skip-khugepaged-file-tests-if-mkfsxfs-is-unavailable.patch selftests-mm-hugetlb-read-hwpoison-add-setup-of-hugetlb-pages.patch selftests-mm-hugetlb_madv_vs_map-fix-tap-plan-mismatches.patch mm-damon-ops-common-fix-age_in_sec-overflow-on-32-bit.patch