The patch titled
Subject: mm/damon/reclaim: fix the timer always stays active
has been added to the -mm tree. Its filename is
mm-damon-reclaim-fix-the-timer-always-stays-active.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-damon-reclaim-fix-the-timer-always-stays-active.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-damon-reclaim-fix-the-timer-always-stays-active.patch
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------------------------------------------------------
From: Hailong Tu <tuhailong@xxxxxxxxx>
Subject: mm/damon/reclaim: fix the timer always stays active
The timer stays active even if the reclaim mechanism is never enabled. It
is unnecessary overhead can be completely avoided by using
module_param_cb() for enabled flag.
Link: https://lkml.kernel.org/r/20220421125910.1052459-1-tuhailong@xxxxxxxxx
Signed-off-by: Hailong Tu <tuhailong@xxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/damon/reclaim.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)
--- a/mm/damon/reclaim.c~mm-damon-reclaim-fix-the-timer-always-stays-active
+++ a/mm/damon/reclaim.c
@@ -28,7 +28,6 @@
* this.
*/
static bool enabled __read_mostly;
-module_param(enabled, bool, 0600);
/*
* Time threshold for cold memory regions identification in microseconds.
@@ -358,11 +357,35 @@ static void damon_reclaim_timer_fn(struc
enabled = last_enabled;
}
- schedule_delayed_work(&damon_reclaim_timer,
+ if (enabled)
+ schedule_delayed_work(&damon_reclaim_timer,
msecs_to_jiffies(ENABLE_CHECK_INTERVAL_MS));
}
static DECLARE_DELAYED_WORK(damon_reclaim_timer, damon_reclaim_timer_fn);
+static int enabled_store(const char *val,
+ const struct kernel_param *kp)
+{
+ int rc = param_set_bool(val, kp);
+
+ if (rc < 0)
+ return rc;
+
+ if (enabled)
+ schedule_delayed_work(&damon_reclaim_timer, 0);
+
+ return 0;
+}
+
+static const struct kernel_param_ops enabled_param_ops = {
+ .set = enabled_store,
+ .get = param_get_bool,
+};
+
+module_param_cb(enabled, &enabled_param_ops, &enabled, 0600);
+MODULE_PARM_DESC(enabled,
+ "Enable or disable DAMON_RECLAIM (default: disabled)");
+
static int damon_reclaim_after_aggregation(struct damon_ctx *c)
{
struct damos *s;
_
Patches currently in -mm which might be from tuhailong@xxxxxxxxx are
mm-damon-reclaim-fix-the-timer-always-stays-active.patch
