Commit 204ab9ab authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs-schemes: implement max_nr_snapshots file 

Add a new DAMON sysfs file for setting and getting the newly introduced
per-DAMON-snapshot level DAMOS deactivation control parameter,
max_nr_snapshots.  The file has a name same to the parameter and placed
under the damos stat directory.

Link: https://lkml.kernel.org/r/20251216080128.42991-9-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 84e425c6

mm/damon/sysfs-schemes.c

+28 −0
Original line number Diff line number Diff line
@@ -205,6 +205,7 @@ struct damon_sysfs_stats { 
	unsigned long sz_ops_filter_passed;

	unsigned long qt_exceeds;

	unsigned long nr_snapshots;

	unsigned long max_nr_snapshots;

};



static struct damon_sysfs_stats *damon_sysfs_stats_alloc(void)
@@ -275,6 +276,28 @@ static ssize_t nr_snapshots_show(struct kobject *kobj, 
	return sysfs_emit(buf, "%lu\n", stats->nr_snapshots);

}



static ssize_t max_nr_snapshots_show(struct kobject *kobj,

		struct kobj_attribute *attr, char *buf)

{

	struct damon_sysfs_stats *stats = container_of(kobj,

			struct damon_sysfs_stats, kobj);



	return sysfs_emit(buf, "%lu\n", stats->max_nr_snapshots);

}



static ssize_t max_nr_snapshots_store(struct kobject *kobj,

		struct kobj_attribute *attr, const char *buf, size_t count)

{

	struct damon_sysfs_stats *stats = container_of(kobj,

			struct damon_sysfs_stats, kobj);

	unsigned long max_nr_snapshots, err = kstrtoul(buf, 0, &max_nr_snapshots);



	if (err)

		return err;

	stats->max_nr_snapshots = max_nr_snapshots;

	return count;

}



static void damon_sysfs_stats_release(struct kobject *kobj)

{

	kfree(container_of(kobj, struct damon_sysfs_stats, kobj));
@@ -301,6 +324,9 @@ static struct kobj_attribute damon_sysfs_stats_qt_exceeds_attr = 
static struct kobj_attribute damon_sysfs_stats_nr_snapshots_attr =

		__ATTR_RO_MODE(nr_snapshots, 0400);



static struct kobj_attribute damon_sysfs_stats_max_nr_snapshots_attr =

		__ATTR_RW_MODE(max_nr_snapshots, 0600);



static struct attribute *damon_sysfs_stats_attrs[] = {

	&damon_sysfs_stats_nr_tried_attr.attr,

	&damon_sysfs_stats_sz_tried_attr.attr,
@@ -309,6 +335,7 @@ static struct attribute *damon_sysfs_stats_attrs[] = { 
	&damon_sysfs_stats_sz_ops_filter_passed_attr.attr,

	&damon_sysfs_stats_qt_exceeds_attr.attr,

	&damon_sysfs_stats_nr_snapshots_attr.attr,

	&damon_sysfs_stats_max_nr_snapshots_attr.attr,

	NULL,

};

ATTRIBUTE_GROUPS(damon_sysfs_stats);
@@ -2732,6 +2759,7 @@ static struct damos *damon_sysfs_mk_scheme( 
		damon_destroy_scheme(scheme);

		return NULL;

	}

	scheme->max_nr_snapshots = sysfs_scheme->stats->max_nr_snapshots;

	return scheme;

}