+ mm-damon-get-the-hotness-from-damon_hot_score-in-damon_pageout_score.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/damon: get the hotness from damon_hot_score() in damon_pageout_score()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-damon-get-the-hotness-from-damon_hot_score-in-damon_pageout_score.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-get-the-hotness-from-damon_hot_score-in-damon_pageout_score.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Kaixu Xia <kaixuxia@tencent.com>
Subject: mm/damon: get the hotness from damon_hot_score() in damon_pageout_score()
Date: Mon, 29 Aug 2022 17:46:06 +0800

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 |   46 +++++-----------------------------------
 1 file changed, 6 insertions(+), 40 deletions(-)

--- a/mm/damon/ops-common.c~mm-damon-get-the-hotness-from-damon_hot_score-in-damon_pageout_score
+++ a/mm/damon/ops-common.c
@@ -88,7 +88,7 @@ void damon_pmdp_mkold(pmd_t *pmd, struct
 #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
 	 */
 	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;
 }
_

Patches currently in -mm which might be from kaixuxia@tencent.com are

mm-damon-core-simplify-the-parameter-passing-for-region-split-operation.patch
mm-damon-simplify-the-parameter-passing-for-check_accesses.patch
mm-damon-vaddr-remove-comparison-between-mm-and-last_mm-when-checking-region-accesses.patch
mm-damon-get-the-hotness-from-damon_hot_score-in-damon_pageout_score.patch