mm/damon/syfs-schemes: implement per-scheme filter-passed bytes stat

Add a new DAMON sysfs interface file under scheme stat directory, namely
'sz_ops_filter_passed'.  It represents total bytes that passed
region-internal DAMOS filters of the scheme that handled by the DAMON
operations set layer.

Link: https://lkml.kernel.org/r/20250106193401.109161-9-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-schemes.c b/mm/damon/sysfs-schemes.c
index 5c4490b97258e46adf9fef9e9297db55630cc344..b447c412b02c5e76e622a771daef41c2f478b499 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -188,6 +188,7 @@ struct damon_sysfs_stats {
        unsigned long sz_tried;
        unsigned long nr_applied;
        unsigned long sz_applied;
+       unsigned long sz_ops_filter_passed;
        unsigned long qt_exceeds;
 };
 
@@ -232,6 +233,15 @@ static ssize_t sz_applied_show(struct kobject *kobj,
        return sysfs_emit(buf, "%lu\n", stats->sz_applied);
 }
 
+static ssize_t sz_ops_filter_passed_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->sz_ops_filter_passed);
+}
+
 static ssize_t qt_exceeds_show(struct kobject *kobj,
                struct kobj_attribute *attr, char *buf)
 {
@@ -258,6 +268,9 @@ static struct kobj_attribute damon_sysfs_stats_nr_applied_attr =
 static struct kobj_attribute damon_sysfs_stats_sz_applied_attr =
                __ATTR_RO_MODE(sz_applied, 0400);
 
+static struct kobj_attribute damon_sysfs_stats_sz_ops_filter_passed_attr =
+               __ATTR_RO_MODE(sz_ops_filter_passed, 0400);
+
 static struct kobj_attribute damon_sysfs_stats_qt_exceeds_attr =
                __ATTR_RO_MODE(qt_exceeds, 0400);
 
@@ -266,6 +279,7 @@ static struct attribute *damon_sysfs_stats_attrs[] = {
        &damon_sysfs_stats_sz_tried_attr.attr,
        &damon_sysfs_stats_nr_applied_attr.attr,
        &damon_sysfs_stats_sz_applied_attr.attr,
+       &damon_sysfs_stats_sz_ops_filter_passed_attr.attr,
        &damon_sysfs_stats_qt_exceeds_attr.attr,
        NULL,
 };
@@ -2077,6 +2091,8 @@ void damon_sysfs_schemes_update_stats(
                sysfs_stats->sz_tried = scheme->stat.sz_tried;
                sysfs_stats->nr_applied = scheme->stat.nr_applied;
                sysfs_stats->sz_applied = scheme->stat.sz_applied;
+               sysfs_stats->sz_ops_filter_passed =
+                       scheme->stat.sz_ops_filter_passed;
                sysfs_stats->qt_exceeds = scheme->stat.qt_exceeds;
        }
 }