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b=Q/aHaq+Oq59ENwXN1PSrrleajOoCVvnhCLjcreyOXd1DAVEfnapa2aTv80PrsuAea KWV/VLnGtFuYtyepU7XkL1YqNvYvyY6hs0WkCit7ck1sH0CEY8M4hjMBu6UKTRfOUg rPlMb83mqr4PnCrEK5F3iCl2kwmgavBNqfBuV4KYx2s1C2Z3Wtj7HWo04kThNAevIM 08b8JoqL79+Yz6lj0FbfSJe+Mp24tdc/y5CMeDWhEHekjSfw2Yj1GSbiyl/w2HMZhA zRTNXzC7KAOO0hd4v+p5i29LdKwzKDeoM+vSykmnhPuFU8u3Ke5Y8UX3W3/1YRfPzK o9n+pAby5fZTQ== From: SJ Park To: Cc: SJ Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 3/6] mm/damon/core: s/nr_accesses_to_accesses_bp/sample_count_to_bp/ Date: Mon, 6 Jul 2026 21:38:23 -0700 Message-ID: <20260707043828.97900-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260707043828.97900-1-sj@kernel.org> References: <20260707043828.97900-1-sj@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 3A82040003 X-Stat-Signature: qgr49asi39qwnepysbret911p8ibkfa9 X-HE-Tag: 1783399144-465664 X-HE-Meta: U2FsdGVkX18KfA/RlDW/UvJ6dQNlJ/ati8Fzsr/69pllgDFMrUxaSqYWtht2QHESBnGlKG1vk7Rj1yXJtYLDAFufLW82xlZkvbamx8iIRH7nQdWNLWVOupTu4QMspvzmF09554syFZEjFnt4+yJLG066EmeVIIy2xVkejTtfatytMEKMULMeaFbfyWMrEG/kZ6p8SBj655Y+Je0AkYhxheffcmWAdEoL+vwu8Qv1a730OoeZOPmVQDP1qZNrQUC7DiD4nmfwBBsfVTQXkSLmZMEFUiaTDl+dHyZfYT37t8NPkR+GIwZuME9Vk8EhsmFDHlvHG+s+oKgKf6/7lkVrWcU9F5fWszxvNT+RxLq3ZFYy6LqBnZ7nY2GkrApwvpwDdS2qzBoAPXClILdgnPIJcbgZcsCqPYbzcTtiXO+tKW81bKSaiYIn+9TNrhyZC0JxE8qcf6DhzVeRvPFFDI/FVSZChQfArHh9kzd/EQoNBtVoYkPCbWkR/klp38MOAYEugx6YEIDYGLR9J4sV6a2fNrjDG5fL45RBxcwwIFfvSOp6+jl9zPyHJsSJiY1hG9OtACNtXpbdmZSeiIXxwzFVmFjuHt1xQgeQjmKOmXPw37/09xfpTZA0wuYrPkGtresjwoAVthUErqq87Z2s4YkdAMWs5YMLK6akef96gZJ386heJ7JFgFwTd03bWHP7sM9wl4segkGrGmkAxhfJgAOkjX6DItYWxaQPPcMkGLzJHYQZT8deVii4tCYKQtSFkXPq3EXGiQHOY+CVuZVlqkfjJ8ia1KqA0jU6GwN5y35Bs1S0PnOoSCGxtT1nKd5ntJ166SOUZb3V28tKQpXVQhZryy80PuTLg1nx65JKKKUyYfYmoJy8UzOpqic6nZm03lzVckRlDLkZh8k7yCDLSEWcyw2YtfVLBFYH0oVExfmN9pflM7LxfsRppCkx0l64b8p6F7zihN2KIdTm1St19se m1zdBDmA l/xSGMRnpK4k2lFdHzABttQgiPuTksLIe2xnv4AQfOnmsyEsVumS9OdROaxe8T7GqsZT4xmm7ctrl/lE46J3RFVL5vh58rSWzjRIUaXMazczqxJULJvJn7JiwitiDVsouz25E0khJ2be196u3j0Or0OCD46pIYsuuzH2Xa9KFOzykMulpt5bjMfNhqFA/YLYXX6Kq8QrhE5tmNakW3urYbcmkEnPhYY6znTplgo+Gy9FOSOUsZvhs2+2/oDhgEbq2hR4uC6UFpXrWc2bgB4sJ82aknw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: damon_nr_accesses_to_accesses_bp() actually converts a positive sample count to the ratio. Rename it to better describe what it really does and not confusing for more general uses. Also remove the obsolete comment about division-by-zero. Commit 35d4a3cf70a8 ("mm/damon/ops-common: handle extreme intervals in damon_hot_score()") modified damon_nr_samples_per_aggr() to always return non-zero. Hence no division-by-zero of the note can happen. Signed-off-by: SJ Park --- mm/damon/core.c | 17 +++++------------ mm/damon/tests/core-kunit.h | 8 ++++---- 2 files changed, 9 insertions(+), 16 deletions(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index ca530faaa4f83..718268df27fa7 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -883,25 +883,18 @@ static unsigned int damon_sample_bp_to_count( return bp * damon_nr_samples_per_aggr(attrs) / 10000; } -/* - * Convert nr_accesses to access ratio in bp (per 10,000). - * - * Callers should ensure attrs.aggr_interval is not zero, like - * damon_update_monitoring_results() does . Otherwise, divide-by-zero would - * happen. - */ -static unsigned int damon_nr_accesses_to_accesses_bp( - unsigned int nr_accesses, struct damon_attrs *attrs) +/* convert sample count to ratio in bp (per 10,000) */ +static unsigned int damon_sample_count_to_bp( + unsigned int count, struct damon_attrs *attrs) { - return mult_frac(nr_accesses, 10000, damon_nr_samples_per_aggr(attrs)); + return mult_frac(count, 10000, damon_nr_samples_per_aggr(attrs)); } static unsigned int damon_nr_accesses_for_new_attrs(unsigned int nr_accesses, struct damon_attrs *old_attrs, struct damon_attrs *new_attrs) { return damon_sample_bp_to_count( - damon_nr_accesses_to_accesses_bp( - nr_accesses, old_attrs), + damon_sample_count_to_bp(nr_accesses, old_attrs), new_attrs); } diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 0124f83b39b83..86eae3a590354 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -575,7 +575,7 @@ static void damon_test_set_regions(struct kunit *test) }, 3); } -static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test) +static void damon_test_sample_count_to_bp(struct kunit *test) { struct damon_attrs attrs = { .sample_interval = 10, @@ -585,7 +585,7 @@ static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test) /* * In some cases such as 32bit architectures where UINT_MAX is * ULONG_MAX, attrs.aggr_interval becomes zero. Calling - * damon_nr_accesses_to_accesses_bp() in the case will cause + * damon_sample_count_to_bp() in the case will cause * divide-by-zero. Such case is prohibited in normal execution since * the caution is documented on the comment for the function, and * damon_update_monitoring_results() does the check. Skip the test in @@ -594,7 +594,7 @@ static void damon_test_nr_accesses_to_accesses_bp(struct kunit *test) if (!attrs.aggr_interval) kunit_skip(test, "aggr_interval is zero."); - KUNIT_EXPECT_EQ(test, damon_nr_accesses_to_accesses_bp(123, &attrs), 0); + KUNIT_EXPECT_EQ(test, damon_sample_count_to_bp(123, &attrs), 0); } static void damon_test_update_monitoring_result(struct kunit *test) @@ -1572,7 +1572,7 @@ static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_split_above_half_progresses), KUNIT_CASE(damon_test_ops_registration), KUNIT_CASE(damon_test_set_regions), - KUNIT_CASE(damon_test_nr_accesses_to_accesses_bp), + KUNIT_CASE(damon_test_sample_count_to_bp), KUNIT_CASE(damon_test_update_monitoring_result), KUNIT_CASE(damon_test_set_attrs), KUNIT_CASE(damon_test_mvsum), -- 2.47.3