Commit 7ee161f1 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs-schemes: implement filter directory 

Implement DAMOS filter directory which will be located under the filters
directory.  The directory provides three files, namely type, matching, and
memcg_path.  'type' and 'matching' will be directly connected to the
fields of 'struct damos_filter' having same name.  'memcg_path' will
receive the path of the memory cgroup of the interest and later converted
to memcg id when it's committed.

Link: https://lkml.kernel.org/r/20221205230830.144349-7-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ac35264b

mm/damon/sysfs-schemes.c

+128 −0
Original line number Diff line number Diff line
@@ -258,6 +258,134 @@ static struct kobj_type damon_sysfs_stats_ktype = { 
	.default_groups = damon_sysfs_stats_groups,

};



/*

 * filter directory

 */



struct damon_sysfs_scheme_filter {

	struct kobject kobj;

	enum damos_filter_type type;

	bool matching;

	char *memcg_path;

};



/* Should match with enum damos_filter_type */

static const char * const damon_sysfs_scheme_filter_type_strs[] = {

	"anon",

	"memcg",

};



static ssize_t type_show(struct kobject *kobj,

		struct kobj_attribute *attr, char *buf)

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);



	return sysfs_emit(buf, "%s\n",

			damon_sysfs_scheme_filter_type_strs[filter->type]);

}



static ssize_t type_store(struct kobject *kobj,

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

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);

	enum damos_filter_type type;

	ssize_t ret = -EINVAL;



	for (type = 0; type < NR_DAMOS_FILTER_TYPES; type++) {

		if (sysfs_streq(buf, damon_sysfs_scheme_filter_type_strs[

					type])) {

			filter->type = type;

			ret = count;

			break;

		}

	}

	return ret;

}



static ssize_t matching_show(struct kobject *kobj,

		struct kobj_attribute *attr, char *buf)

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);



	return sysfs_emit(buf, "%c\n", filter->matching ? 'Y' : 'N');

}



static ssize_t matching_store(struct kobject *kobj,

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

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);

	bool matching;

	int err = kstrtobool(buf, &matching);



	if (err)

		return err;



	filter->matching = matching;

	return count;

}



static ssize_t memcg_path_show(struct kobject *kobj,

		struct kobj_attribute *attr, char *buf)

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);



	return sysfs_emit(buf, "%s\n",

			filter->memcg_path ? filter->memcg_path : "");

}



static ssize_t memcg_path_store(struct kobject *kobj,

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

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);

	char *path = kmalloc(sizeof(*path) * (count + 1), GFP_KERNEL);



	if (!path)

		return -ENOMEM;



	strncpy(path, buf, count);

	path[count] = '\0';

	filter->memcg_path = path;

	return count;

}



static void damon_sysfs_scheme_filter_release(struct kobject *kobj)

{

	struct damon_sysfs_scheme_filter *filter = container_of(kobj,

			struct damon_sysfs_scheme_filter, kobj);



	kfree(filter->memcg_path);

	kfree(filter);

}



static struct kobj_attribute damon_sysfs_scheme_filter_type_attr =

		__ATTR_RW_MODE(type, 0600);



static struct kobj_attribute damon_sysfs_scheme_filter_matching_attr =

		__ATTR_RW_MODE(matching, 0600);



static struct kobj_attribute damon_sysfs_scheme_filter_memcg_path_attr =

		__ATTR_RW_MODE(memcg_path, 0600);



static struct attribute *damon_sysfs_scheme_filter_attrs[] = {

	&damon_sysfs_scheme_filter_type_attr.attr,

	&damon_sysfs_scheme_filter_matching_attr.attr,

	&damon_sysfs_scheme_filter_memcg_path_attr.attr,

	NULL,

};

ATTRIBUTE_GROUPS(damon_sysfs_scheme_filter);



static struct kobj_type damon_sysfs_scheme_filter_ktype = {

	.release = damon_sysfs_scheme_filter_release,

	.sysfs_ops = &kobj_sysfs_ops,

	.default_groups = damon_sysfs_scheme_filter_groups,

};



/*

 * filters directory

 */