mm/damon/sysfs-schemes: expose per-region filter-passed bytes

Per-region operations set-handled DAMOS filters passed memory size
information is provided to only DAMON core API users.  Further expose it
to the user space by adding a new DAMON sysfs interface file under each
scheme tried region directory.

Link: https://lkml.kernel.org/r/20250106193401.109161-14-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/sysfs-common.h b/mm/damon/sysfs-common.h
index b3f63bc658b7bf9a1dae1d5c0b9aaeb8e1f213e8..70d84bdc9f5fad5f21f6f1412152f481cdb8f975 100644 (file)
--- a/mm/damon/sysfs-common.h
+++ b/mm/damon/sysfs-common.h
@@ -48,7 +48,7 @@ void damon_sysfs_schemes_update_stats(
 void damos_sysfs_populate_region_dir(struct damon_sysfs_schemes *sysfs_schemes,
                struct damon_ctx *ctx, struct damon_target *t,
                struct damon_region *r, struct damos *s,
-               bool total_bytes_only);
+               bool total_bytes_only, unsigned long sz_filter_passed);
 
 int damon_sysfs_schemes_clear_regions(
                struct damon_sysfs_schemes *sysfs_schemes);

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index b447c412b02c5e76e622a771daef41c2f478b499..deeaf23c1fcfdd260fb3bca118e7e10688a99016 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -19,6 +19,7 @@ struct damon_sysfs_scheme_region {
        struct damon_addr_range ar;
        unsigned int nr_accesses;
        unsigned int age;
+       unsigned long sz_filter_passed;
        struct list_head list;
 };
 
@@ -74,6 +75,15 @@ static ssize_t age_show(struct kobject *kobj, struct kobj_attribute *attr,
        return sysfs_emit(buf, "%u\n", region->age);
 }
 
+static ssize_t sz_filter_passed_show(struct kobject *kobj,
+               struct kobj_attribute *attr, char *buf)
+{
+       struct damon_sysfs_scheme_region *region = container_of(kobj,
+                       struct damon_sysfs_scheme_region, kobj);
+
+       return sysfs_emit(buf, "%lu\n", region->sz_filter_passed);
+}
+
 static void damon_sysfs_scheme_region_release(struct kobject *kobj)
 {
        struct damon_sysfs_scheme_region *region = container_of(kobj,
@@ -95,11 +105,15 @@ static struct kobj_attribute damon_sysfs_scheme_region_nr_accesses_attr =
 static struct kobj_attribute damon_sysfs_scheme_region_age_attr =
                __ATTR_RO_MODE(age, 0400);
 
+static struct kobj_attribute damon_sysfs_scheme_region_sz_filter_passed_attr =
+               __ATTR_RO_MODE(sz_filter_passed, 0400);
+
 static struct attribute *damon_sysfs_scheme_region_attrs[] = {
        &damon_sysfs_scheme_region_start_attr.attr,
        &damon_sysfs_scheme_region_end_attr.attr,
        &damon_sysfs_scheme_region_nr_accesses_attr.attr,
        &damon_sysfs_scheme_region_age_attr.attr,
+       &damon_sysfs_scheme_region_sz_filter_passed_attr.attr,
        NULL,
 };
 ATTRIBUTE_GROUPS(damon_sysfs_scheme_region);
@@ -2105,12 +2119,14 @@ void damon_sysfs_schemes_update_stats(
  * @r:                 DAMON region to populate the directory for.
  * @s:                 Corresponding scheme.
  * @total_bytes_only:  Whether the request is for bytes update only.
+ * @sz_filter_passed:  Bytes of @r that passed filters of @s.
  *
  * Called from DAMOS walk callback while holding damon_sysfs_lock.
  */
 void damos_sysfs_populate_region_dir(struct damon_sysfs_schemes *sysfs_schemes,
                struct damon_ctx *ctx, struct damon_target *t,
-               struct damon_region *r, struct damos *s, bool total_bytes_only)
+               struct damon_region *r, struct damos *s, bool total_bytes_only,
+               unsigned long sz_filter_passed)
 {
        struct damos *scheme;
        struct damon_sysfs_scheme_regions *sysfs_regions;
@@ -2135,6 +2151,7 @@ void damos_sysfs_populate_region_dir(struct damon_sysfs_schemes *sysfs_schemes,
        region = damon_sysfs_scheme_region_alloc(r);
        if (!region)
                return;
+       region->sz_filter_passed = sz_filter_passed;
        list_add_tail(&region->list, &sysfs_regions->regions_list);
        sysfs_regions->nr_regions++;
        if (kobject_init_and_add(&region->kobj,

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 224873ca8aa68bcf05ee7ce3b16aee9f13bdc4e3..deeab04d3b46f93f3074f84e653c21999d04d460 100644 (file)
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1461,7 +1461,8 @@ static void damon_sysfs_schemes_tried_regions_upd_one(void *data, struct damon_c
 
        damos_sysfs_populate_region_dir(
                        sysfs_kdamond->contexts->contexts_arr[0]->schemes,
-                       ctx, t, r, s, walk_data->total_bytes_only);
+                       ctx, t, r, s, walk_data->total_bytes_only,
+                       sz_filter_passed);
 }
 
 static int damon_sysfs_update_schemes_tried_regions(