diff options
| author | SeongJae Park <sj@kernel.org> | 2022-06-13 19:22:56 +0000 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-07-03 18:08:42 -0700 |
| commit | 8cdcc532268df0893d9756f537cbce479f4c4831 (patch) | |
| tree | 2077cacb9fcb45632ce47c34000e80cab4f3051e /mm/damon/ops-common.c | |
| parent | 0e93e8bfd0b8b953038785109d0bab72280823f6 (diff) | |
mm/damon/schemes: add 'LRU_PRIO' DAMOS action
This commit adds a new DAMOS action called 'LRU_PRIO' for the physical
address space. The action prioritizes pages in the memory regions of the
user-specified target access pattern on their LRU lists. This is hence
supposed to be used for frequently accessed (hot) memory regions so that
hot pages could be more likely protected under memory pressure.
Internally, it simply calls 'mark_page_accessed()'.
Link: https://lkml.kernel.org/r/20220613192301.8817-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/damon/ops-common.c')
| -rw-r--r-- | mm/damon/ops-common.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c index 10ef20b2003f..b1335de200e7 100644 --- a/mm/damon/ops-common.c +++ b/mm/damon/ops-common.c @@ -130,3 +130,45 @@ int damon_pageout_score(struct damon_ctx *c, struct damon_region *r, /* Return coldness of the region */ return DAMOS_MAX_SCORE - hotness; } + +int damon_hot_score(struct damon_ctx *c, struct damon_region *r, + struct damos *s) +{ + unsigned int max_nr_accesses; + int freq_subscore; + unsigned int 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; + int hotness; + + max_nr_accesses = c->aggr_interval / c->sample_interval; + freq_subscore = r->nr_accesses * DAMON_MAX_SUBSCORE / max_nr_accesses; + + age_in_sec = (unsigned long)r->age * c->aggr_interval / 1000000; + for (age_in_log = 0; age_in_log < DAMON_MAX_AGE_IN_LOG && age_in_sec; + age_in_log++, age_in_sec >>= 1) + ; + + /* If frequency is 0, higher age means it's colder */ + if (freq_subscore == 0) + age_in_log *= -1; + + /* + * Now age_in_log is in [-DAMON_MAX_AGE_IN_LOG, DAMON_MAX_AGE_IN_LOG]. + * Scale it to be in [0, 100] and set it as age subscore. + */ + age_in_log += DAMON_MAX_AGE_IN_LOG; + age_subscore = age_in_log * DAMON_MAX_SUBSCORE / + DAMON_MAX_AGE_IN_LOG / 2; + + hotness = (freq_weight * freq_subscore + age_weight * age_subscore); + if (freq_weight + age_weight) + hotness /= freq_weight + age_weight; + /* + * Transform it to fit in [0, DAMOS_MAX_SCORE] + */ + hotness = hotness * DAMOS_MAX_SCORE / DAMON_MAX_SUBSCORE; + + return hotness; +} |