linux-kernel - [PATCH V3] mm/damon: simplify scheme create in lru

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Message-Id: <20220915023655.41923-1-xhao@linux.alibaba.com>
Date:   Thu, 15 Sep 2022 10:36:55 +0800
From:   Xin Hao <xhao@...ux.alibaba.com>
To:     sj@...nel.org
Cc:     akpm@...ux-foundation.org, damon@...ts.linux.dev,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        xhao@...ux.alibaba.com
Subject: [PATCH V3] mm/damon: simplify scheme create in lru_sort.c

In damon_lru_sort_new_hot_scheme() and damon_lru_sort_new_cold_scheme(),
they have so much in common, so we can combine them into a single
function, and we just need to distinguish their differences.

Suggested-by: SeongJae Park <sj@...nel.org>
Signed-off-by: Xin Hao <xhao@...ux.alibaba.com>
Changes from v2
(https://lore.kernel.org/linux-mm/20220914113859.37637-1-xhao@linux.alibaba.com/)
- Add static global 'struct damos_access_pattern' stub variable
---
 mm/damon/lru_sort.c | 41 +++++++++++++++++++----------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 07a0908963fd..6a26c5822286 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -132,6 +132,18 @@ DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_lru_sort_cold_stat,
 		lru_sort_tried_cold_regions, lru_sorted_cold_regions,
 		cold_quota_exceeds);

+struct damos_access_pattern damon_lru_sort_stub_access_pattern = {
+	/* Find regions having PAGE_SIZE or larger size */
+	.min_sz_region = PAGE_SIZE,
+	.max_sz_region = ULONG_MAX,
+	/* and accessed for more than the threshold */
+	.min_nr_accesses = 0,
+	.max_nr_accesses = UINT_MAX,
+	/* no matter its age */
+	.min_age_region = 0,
+	.max_age_region = UINT_MAX,
+};
+
 static struct damon_ctx *ctx;
 static struct damon_target *target;

@@ -157,17 +169,9 @@ static struct damos *damon_lru_sort_new_scheme(
 /* Create a DAMON-based operation scheme for hot memory regions */
 static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
 {
-	struct damos_access_pattern pattern = {
-		/* Find regions having PAGE_SIZE or larger size */
-		.min_sz_region = PAGE_SIZE,
-		.max_sz_region = ULONG_MAX,
-		/* and accessed for more than the threshold */
-		.min_nr_accesses = hot_thres,
-		.max_nr_accesses = UINT_MAX,
-		/* no matter its age */
-		.min_age_region = 0,
-		.max_age_region = UINT_MAX,
-	};
+	struct damos_access_pattern pattern = damon_lru_sort_stub_access_pattern;
+
+	pattern.min_nr_accesses = hot_thres;

 	return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_PRIO);
 }
@@ -175,17 +179,10 @@ static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
 /* Create a DAMON-based operation scheme for cold memory regions */
 static struct damos *damon_lru_sort_new_cold_scheme(unsigned int cold_thres)
 {
-	struct damos_access_pattern pattern = {
-		/* Find regions having PAGE_SIZE or larger size */
-		.min_sz_region = PAGE_SIZE,
-		.max_sz_region = ULONG_MAX,
-		/* and not accessed at all */
-		.min_nr_accesses = 0,
-		.max_nr_accesses = 0,
-		/* for min_age or more micro-seconds */
-		.min_age_region = cold_thres,
-		.max_age_region = UINT_MAX,
-	};
+	struct damos_access_pattern pattern = damon_lru_sort_stub_access_pattern;
+
+	pattern.max_nr_accesses = 0;
+	pattern.min_age_region = cold_thres;

 	return damon_lru_sort_new_scheme(&pattern, DAMOS_LRU_DEPRIO);
 }
--
2.31.0