From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org, stable@vger.kernel.org,
acsjakub@amazon.de, sj@kernel.org, akpm@linux-foundation.org
Subject: [merged mm-stable] mm-damon-lru_sort-avoid-divide-by-zero-in-hot-threshold-calculation.patch removed from -mm tree
Date: Wed, 25 Oct 2023 16:49:16 -0700 [thread overview]
Message-ID: <20231025234916.E5A16C433CC@smtp.kernel.org> (raw)
The quilt patch titled
Subject: mm/damon/lru_sort: avoid divide-by-zero in hot threshold calculation
has been removed from the -mm tree. Its filename was
mm-damon-lru_sort-avoid-divide-by-zero-in-hot-threshold-calculation.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 <sj@kernel.org>
Subject: mm/damon/lru_sort: avoid divide-by-zero in hot threshold calculation
Date: Thu, 19 Oct 2023 19:49:23 +0000
When calculating the hotness threshold for lru_prio scheme of
DAMON_LRU_SORT, the module divides some values by the maximum nr_accesses.
However, due to the type of the related variables, simple division-based
calculation of the divisor can return zero. As a result, divide-by-zero
is possible. Fix it by using damon_max_nr_accesses(), which handles the
case.
Link: https://lkml.kernel.org/r/20231019194924.100347-5-sj@kernel.org
Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Jakub Acs <acsjakub@amazon.de>
Cc: <stable@vger.kernel.org> [6.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/damon/lru_sort.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/mm/damon/lru_sort.c~mm-damon-lru_sort-avoid-divide-by-zero-in-hot-threshold-calculation
+++ a/mm/damon/lru_sort.c
@@ -195,9 +195,7 @@ static int damon_lru_sort_apply_paramete
if (err)
return err;
- /* aggr_interval / sample_interval is the maximum nr_accesses */
- hot_thres = damon_lru_sort_mon_attrs.aggr_interval /
- damon_lru_sort_mon_attrs.sample_interval *
+ hot_thres = damon_max_nr_accesses(&damon_lru_sort_mon_attrs) *
hot_thres_access_freq / 1000;
scheme = damon_lru_sort_new_hot_scheme(hot_thres);
if (!scheme)
_
Patches currently in -mm which might be from sj@kernel.org are
mm-damon-sysfs-remove-requested-targets-when-online-commit-inputs.patch
reply other threads:[~2023-10-25 23:51 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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