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

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Message-Id: <20220913152245.25224-1-xhao@linux.alibaba.com>
Date:   Tue, 13 Sep 2022 23:22:45 +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] 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.

Signed-off-by: Xin Hao <xhao@...ux.alibaba.com>
---
 mm/damon/lru_sort.c | 82 +++++++++++++++++----------------------------
 1 file changed, 30 insertions(+), 52 deletions(-)

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 8415e18fcf0e..62063ed43224 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -257,15 +257,15 @@ module_param(nr_cold_quota_exceeds, ulong, 0400);
 static struct damon_ctx *ctx;
 static struct damon_target *target;

-/* Create a DAMON-based operation scheme for hot memory regions */
-static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
+static inline struct damos *damon_lru_sort_new_scheme(unsigned int thres,
+						      enum damos_action action)
 {
 	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,
+		.min_nr_accesses = 0,
 		.max_nr_accesses = UINT_MAX,
 		/* no matter its age */
 		.min_age_region = 0,
@@ -292,60 +292,38 @@ static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
 		.weight_age = 0,
 	};

-	return damon_new_scheme(
-			&pattern,
-			/* prioritize those on LRU lists, as soon as found */
-			DAMOS_LRU_PRIO,
-			/* under the quota. */
-			&quota,
-			/* (De)activate this according to the watermarks. */
-			&wmarks);
+	switch (action) {
+	case DAMOS_LRU_PRIO:
+		pattern.min_nr_accesses = thres;
+		break;
+	case DAMOS_LRU_DEPRIO:
+		pattern.min_age_region = thres;
+		quota.weight_nr_accesses = 0;
+		quota.weight_age = 1;
+		break;
+	default:
+		return NULL;
+	}
+
+	return damon_new_scheme(&pattern,
+				/* mark those as not accessed, as soon as found */
+				action,
+				/* under the quota. */
+				&quota,
+				/* (De)activate this according to the watermarks. */
+				&wmarks);
+}
+
+/* Create a DAMON-based operation scheme for hot memory regions */
+static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
+{
+	return damon_lru_sort_new_scheme(hot_thres, DAMOS_LRU_PRIO);
 }

 /* 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_watermarks wmarks = {
-		.metric = DAMOS_WMARK_FREE_MEM_RATE,
-		.interval = wmarks_interval,
-		.high = wmarks_high,
-		.mid = wmarks_mid,
-		.low = wmarks_low,
-	};
-	struct damos_quota quota = {
-		/*
-		 * Do not try LRU-lists sorting of cold pages for more than
-		 * half of quota_ms milliseconds within
-		 * quota_reset_interval_ms.
-		 */
-		.ms = quota_ms / 2,
-		.sz = 0,
-		.reset_interval = quota_reset_interval_ms,
-		/* Within the quota, mark colder regions not accessed first. */
-		.weight_sz = 0,
-		.weight_nr_accesses = 0,
-		.weight_age = 1,
-	};
-
-	return damon_new_scheme(
-			&pattern,
-			/* mark those as not accessed, as soon as found */
-			DAMOS_LRU_DEPRIO,
-			/* under the quota. */
-			&quota,
-			/* (De)activate this according to the watermarks. */
-			&wmarks);
+	return damon_lru_sort_new_scheme(cold_thres, DAMOS_LRU_DEPRIO);
 }

 static int damon_lru_sort_apply_parameters(void)
--
2.31.0