mm/damon: get the hotness from damon_hot_score() in damon_pageout_score()
authorKaixu Xia <kaixuxia@tencent.com>
Mon, 29 Aug 2022 09:46:06 +0000 (17:46 +0800)
committerAndrew Morton <akpm@linux-foundation.org>
Mon, 12 Sep 2022 03:26:05 +0000 (20:26 -0700)
We can get the hotness value from damon_hot_score() directly in
damon_pageout_score() function and improve the code readability.

Link: https://lkml.kernel.org/r/1661766366-20998-1-git-send-email-kaixuxia@tencent.com
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/damon/ops-common.c

index b1335de..f599838 100644 (file)
@@ -88,7 +88,7 @@ void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr)
 #define DAMON_MAX_SUBSCORE     (100)
 #define DAMON_MAX_AGE_IN_LOG   (32)
 
-int damon_pageout_score(struct damon_ctx *c, struct damon_region *r,
+int damon_hot_score(struct damon_ctx *c, struct damon_region *r,
                        struct damos *s)
 {
        unsigned int max_nr_accesses;
@@ -127,48 +127,14 @@ int damon_pageout_score(struct damon_ctx *c, struct damon_region *r,
         */
        hotness = hotness * DAMOS_MAX_SCORE / DAMON_MAX_SUBSCORE;
 
-       /* Return coldness of the region */
-       return DAMOS_MAX_SCORE - hotness;
+       return hotness;
 }
 
-int damon_hot_score(struct damon_ctx *c, struct damon_region *r,
+int damon_pageout_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;
+       int hotness = damon_hot_score(c, r, s);
 
-       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;
+       /* Return coldness of the region */
+       return DAMOS_MAX_SCORE - hotness;
 }