1 files changed, 58 insertions, 5 deletions

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index cd6815ecc04e..e2bd2d7becdd 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -212,6 +212,7 @@ struct damon_sysfs_target {
 	struct kobject kobj;
 	struct damon_sysfs_regions *regions;
 	int pid;
+	bool obsolete;
 };
 
 static struct damon_sysfs_target *damon_sysfs_target_alloc(void)
@@ -263,6 +264,29 @@ static ssize_t pid_target_store(struct kobject *kobj,
 	return count;
 }
 
+static ssize_t obsolete_target_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	struct damon_sysfs_target *target = container_of(kobj,
+			struct damon_sysfs_target, kobj);
+
+	return sysfs_emit(buf, "%c\n", target->obsolete ? 'Y' : 'N');
+}
+
+static ssize_t obsolete_target_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	struct damon_sysfs_target *target = container_of(kobj,
+			struct damon_sysfs_target, kobj);
+	bool obsolete;
+	int err = kstrtobool(buf, &obsolete);
+
+	if (err)
+		return err;
+	target->obsolete = obsolete;
+	return count;
+}
+
 static void damon_sysfs_target_release(struct kobject *kobj)
 {
 	kfree(container_of(kobj, struct damon_sysfs_target, kobj));
@@ -271,8 +295,12 @@ static void damon_sysfs_target_release(struct kobject *kobj)
 static struct kobj_attribute damon_sysfs_target_pid_attr =
 		__ATTR_RW_MODE(pid_target, 0600);
 
+static struct kobj_attribute damon_sysfs_target_obsolete_attr =
+		__ATTR_RW_MODE(obsolete_target, 0600);
+
 static struct attribute *damon_sysfs_target_attrs[] = {
 	&damon_sysfs_target_pid_attr.attr,
+	&damon_sysfs_target_obsolete_attr.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(damon_sysfs_target);
@@ -1264,7 +1292,7 @@ enum damon_sysfs_cmd {
 	DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS,
 	/*
 	 * @DAMON_SYSFS_CMD_UPDATE_TUNED_INTERVALS: Update the tuned monitoring
-	 * intevals.
+	 * intervals.
 	 */
 	DAMON_SYSFS_CMD_UPDATE_TUNED_INTERVALS,
 	/*
@@ -1377,6 +1405,7 @@ static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,
 			/* caller will destroy targets */
 			return -EINVAL;
 	}
+	t->obsolete = sys_target->obsolete;
 	return damon_sysfs_set_regions(t, sys_target->regions, ctx->min_sz_region);
 }
 
@@ -1452,6 +1481,26 @@ static struct damon_ctx *damon_sysfs_build_ctx(
 		struct damon_sysfs_context *sys_ctx);
 
 /*
+ * Return a new damon_ctx for testing new parameters to commit.
+ */
+static struct damon_ctx *damon_sysfs_new_test_ctx(
+		struct damon_ctx *running_ctx)
+{
+	struct damon_ctx *test_ctx;
+	int err;
+
+	test_ctx = damon_new_ctx();
+	if (!test_ctx)
+		return NULL;
+	err = damon_commit_ctx(test_ctx, running_ctx);
+	if (err) {
+		damon_destroy_ctx(test_ctx);
+		return NULL;
+	}
+	return test_ctx;
+}
+
+/*
  * damon_sysfs_commit_input() - Commit user inputs to a running kdamond.
  * @kdamond:	The kobject wrapper for the associated kdamond.
  *
@@ -1472,7 +1521,7 @@ static int damon_sysfs_commit_input(void *data)
 	param_ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
 	if (IS_ERR(param_ctx))
 		return PTR_ERR(param_ctx);
-	test_ctx = damon_new_ctx();
+	test_ctx = damon_sysfs_new_test_ctx(kdamond->damon_ctx);
 	if (!test_ctx)
 		return -ENOMEM;
 	err = damon_commit_ctx(test_ctx, param_ctx);
@@ -1552,16 +1601,17 @@ static struct damon_ctx *damon_sysfs_build_ctx(
 	return ctx;
 }
 
+static unsigned long damon_sysfs_next_update_jiffies;
+
 static int damon_sysfs_repeat_call_fn(void *data)
 {
 	struct damon_sysfs_kdamond *sysfs_kdamond = data;
-	static unsigned long next_update_jiffies;
 
 	if (!sysfs_kdamond->refresh_ms)
 		return 0;
-	if (time_before(jiffies, next_update_jiffies))
+	if (time_before(jiffies, damon_sysfs_next_update_jiffies))
 		return 0;
-	next_update_jiffies = jiffies +
+	damon_sysfs_next_update_jiffies = jiffies +
 		msecs_to_jiffies(sysfs_kdamond->refresh_ms);
 
 	if (!mutex_trylock(&damon_sysfs_lock))
@@ -1607,6 +1657,9 @@ static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
 	}
 	kdamond->damon_ctx = ctx;
 
+	damon_sysfs_next_update_jiffies =
+		jiffies + msecs_to_jiffies(kdamond->refresh_ms);
+
 	repeat_call_control->fn = damon_sysfs_repeat_call_fn;
 	repeat_call_control->data = kdamond;
 	repeat_call_control->repeat = true;