Messages in this thread Patch in this message | | | From | SeongJae Park <> | Subject | [PATCH v2 4/5] mm/damon/lru_sort: avoid divide-by-zero in hot threshold calculation | Date | Fri, 20 Oct 2023 17:23:16 +0000 |
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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.
Reported-by: Jakub Acs <acsjakub@amazon.de> Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting") Cc: <stable@vger.kernel.org> # 6.0.x Signed-off-by: SeongJae Park <sj@kernel.org> --- mm/damon/lru_sort.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c index 3ecdcc029443..f2e5f9431892 100644 --- a/mm/damon/lru_sort.c +++ b/mm/damon/lru_sort.c @@ -195,9 +195,7 @@ static int damon_lru_sort_apply_parameters(void) 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) -- 2.34.1
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