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| author | SeongJae Park <sj@kernel.org> | 2023-10-19 19:49:23 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-25 16:47:15 -0700 |
| commit | 44063f125af4bb4efd1d500d8091fa33a98af325 (patch) | |
| tree | 20c83e3ff9e7e696515145b58ac425be20c46958 /mm | |
| parent | 3bafc47d3c4a2fc4d3b382aeb3c087f8fc84d9fd (diff) | |
| download | lwn-44063f125af4bb4efd1d500d8091fa33a98af325.tar.gz lwn-44063f125af4bb4efd1d500d8091fa33a98af325.zip | |
mm/damon/lru_sort: avoid divide-by-zero in hot threshold calculation
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/damon/lru_sort.c | 4 |
1 files changed, 1 insertions, 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) |