mm/damon/reclaim: use watermarks parameters generator macro

This commit makes DAMON_RECLAIM to generate the module parameters for
DAMOS watermarks using the generator macro to simplify the code and reduce
duplicates.

Link: https://lkml.kernel.org/r/20220913174449.50645-15-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/reclaim.c

@@ -91,45 +91,14 @@ module_param(quota_sz, ulong, 0600);
 static unsigned long quota_reset_interval_ms __read_mostly = 1000;
 module_param(quota_reset_interval_ms, ulong, 0600);
 
-/*
- * The watermarks check time interval in microseconds.
- *
- * Minimal time to wait before checking the watermarks, when DAMON_RECLAIM is
- * enabled but inactive due to its watermarks rule.  5 seconds by default.
- */
-static unsigned long wmarks_interval __read_mostly = 5000000;
-module_param(wmarks_interval, ulong, 0600);
-
-/*
- * Free memory rate (per thousand) for the high watermark.
- *
- * If free memory of the system in bytes per thousand bytes is higher than
- * this, DAMON_RECLAIM becomes inactive, so it does nothing but periodically
- * checks the watermarks.  500 (50%) by default.
- */
-static unsigned long wmarks_high __read_mostly = 500;
-module_param(wmarks_high, ulong, 0600);
-
-/*
- * Free memory rate (per thousand) for the middle watermark.
- *
- * If free memory of the system in bytes per thousand bytes is between this and
- * the low watermark, DAMON_RECLAIM becomes active, so starts the monitoring
- * and the reclaiming.  400 (40%) by default.
- */
-static unsigned long wmarks_mid __read_mostly = 400;
-module_param(wmarks_mid, ulong, 0600);
-
-/*
- * Free memory rate (per thousand) for the low watermark.
- *
- * If free memory of the system in bytes per thousand bytes is lower than this,
- * DAMON_RECLAIM becomes inactive, so it does nothing but periodically checks
- * the watermarks.  In the case, the system falls back to the LRU-based page
- * granularity reclamation logic.  200 (20%) by default.
- */
-static unsigned long wmarks_low __read_mostly = 200;
-module_param(wmarks_low, ulong, 0600);
+struct damos_watermarks damon_reclaim_wmarks = {
+	.metric = DAMOS_WMARK_FREE_MEM_RATE,
+	.interval = 5000000,	/* 5 seconds */
+	.high = 500,		/* 50 percent */
+	.mid = 400,		/* 40 percent */
+	.low = 200,		/* 20 percent */
+};
+DEFINE_DAMON_MODULES_WMARKS_PARAMS(damon_reclaim_wmarks);
 
 static struct damon_attrs damon_reclaim_mon_attrs = {
 	.sample_interval = 5000,	/* 5 ms */
@@ -214,13 +183,6 @@ static struct damos *damon_reclaim_new_scheme(void)
 			damon_reclaim_mon_attrs.aggr_interval,
 		.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 reclamation for more than quota_ms milliseconds
@@ -242,7 +204,7 @@ static struct damos *damon_reclaim_new_scheme(void)
 			/* under the quota. */
 			&quota,
 			/* (De)activate this according to the watermarks. */
-			&wmarks);
+			&damon_reclaim_wmarks);
 }
 
 static int damon_reclaim_apply_parameters(void)