From: SeongJae Park <sj@kernel.org>
Date: Tue, 16 Sep 2025 03:35:06 +0000 (-0700)
Subject: mm/damon/stat: use damon_initialized()
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=b663f17b738f4a9a9f599dff1bed8e4db519e6f8;p=users%2Fhch%2Fmisc.git

mm/damon/stat: use damon_initialized()

DAMON_STAT is assuming DAMON is ready to use in module_init time, and uses
its own hack to see if it is the time.  Use damon_initialized(), which is
a way for seeing if DAMON is ready to be used that is more reliable and
better to maintain instead of the hack.

Link: https://lkml.kernel.org/r/20250916033511.116366-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/mm/damon/stat.c b/mm/damon/stat.c
index 87bcd8866d4b..c4fbd8cfa5eb 100644
--- a/mm/damon/stat.c
+++ b/mm/damon/stat.c
@@ -214,8 +214,6 @@ static void damon_stat_stop(void)
 	damon_destroy_ctx(damon_stat_context);
 }
 
-static bool damon_stat_init_called;
-
 static int damon_stat_enabled_store(
 		const char *val, const struct kernel_param *kp)
 {
@@ -229,7 +227,7 @@ static int damon_stat_enabled_store(
 	if (is_enabled == enabled)
 		return 0;
 
-	if (!damon_stat_init_called)
+	if (!damon_initialized())
 		/*
 		 * probably called from command line parsing (parse_args()).
 		 * Cannot call damon_new_ctx().  Let damon_stat_init() handle.
@@ -250,12 +248,16 @@ static int __init damon_stat_init(void)
 {
 	int err = 0;
 
-	damon_stat_init_called = true;
+	if (!damon_initialized()) {
+		err = -ENOMEM;
+		goto out;
+	}
 
 	/* probably set via command line */
 	if (enabled)
 		err = damon_stat_start();
 
+out:
 	if (err && enabled)
 		enabled = false;
 	return err;