Commit 8eabc77c authored by Kaixu Xia's avatar Kaixu Xia Committed by Andrew Morton
Browse files

mm/damon: get the hotness from damon_hot_score() in damon_pageout_score() 

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: default avatarKaixu Xia <kaixuxia@tencent.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent bcd0dea5

mm/damon/ops-common.c

+6 −40
Original line number Diff line number Diff line
@@ -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;

}