mm/damon/sysfs: implement intervals tuning goal directory

Implement DAMON sysfs interface directory and its files for setting DAMON
sampling and aggregation intervals auto-tuning goal.

Link: https://lkml.kernel.org/r/20250303221726.484227-4-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.c b/mm/damon/sysfs.c
index deeab04d3b46f93f3074f84e653c21999d04d460..a772060300b426c19eb1d7a24f04de5683efd132 100644 (file)
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -408,6 +408,164 @@ static const struct kobj_type damon_sysfs_targets_ktype = {
        .default_groups = damon_sysfs_targets_groups,
 };
 
+/*
+ * intervals goal directory
+ */
+
+struct damon_sysfs_intervals_goal {
+       struct kobject kobj;
+       unsigned long access_bp;
+       unsigned long aggrs;
+       unsigned long min_sample_us;
+       unsigned long max_sample_us;
+};
+
+static struct damon_sysfs_intervals_goal *damon_sysfs_intervals_goal_alloc(
+               unsigned long access_bp, unsigned long aggrs,
+               unsigned long min_sample_us, unsigned long max_sample_us)
+{
+       struct damon_sysfs_intervals_goal *goal = kmalloc(sizeof(*goal),
+                       GFP_KERNEL);
+
+       if (!goal)
+               return NULL;
+
+       goal->kobj = (struct kobject){};
+       goal->access_bp = access_bp;
+       goal->aggrs = aggrs;
+       goal->min_sample_us = min_sample_us;
+       goal->max_sample_us = max_sample_us;
+       return goal;
+}
+
+static ssize_t access_bp_show(struct kobject *kobj,
+               struct kobj_attribute *attr, char *buf)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+
+       return sysfs_emit(buf, "%lu\n", goal->access_bp);
+}
+
+static ssize_t access_bp_store(struct kobject *kobj,
+               struct kobj_attribute *attr, const char *buf, size_t count)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+       unsigned long nr;
+       int err = kstrtoul(buf, 0, &nr);
+
+       if (err)
+               return err;
+
+       goal->access_bp = nr;
+       return count;
+}
+
+static ssize_t aggrs_show(struct kobject *kobj,
+               struct kobj_attribute *attr, char *buf)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+
+       return sysfs_emit(buf, "%lu\n", goal->aggrs);
+}
+
+static ssize_t aggrs_store(struct kobject *kobj,
+               struct kobj_attribute *attr, const char *buf, size_t count)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+       unsigned long nr;
+       int err = kstrtoul(buf, 0, &nr);
+
+       if (err)
+               return err;
+
+       goal->aggrs = nr;
+       return count;
+}
+
+static ssize_t min_sample_us_show(struct kobject *kobj,
+               struct kobj_attribute *attr, char *buf)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+
+       return sysfs_emit(buf, "%lu\n", goal->min_sample_us);
+}
+
+static ssize_t min_sample_us_store(struct kobject *kobj,
+               struct kobj_attribute *attr, const char *buf, size_t count)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+       unsigned long nr;
+       int err = kstrtoul(buf, 0, &nr);
+
+       if (err)
+               return err;
+
+       goal->min_sample_us = nr;
+       return count;
+}
+
+static ssize_t max_sample_us_show(struct kobject *kobj,
+               struct kobj_attribute *attr, char *buf)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+
+       return sysfs_emit(buf, "%lu\n", goal->max_sample_us);
+}
+
+static ssize_t max_sample_us_store(struct kobject *kobj,
+               struct kobj_attribute *attr, const char *buf, size_t count)
+{
+       struct damon_sysfs_intervals_goal *goal = container_of(kobj,
+                       struct damon_sysfs_intervals_goal, kobj);
+       unsigned long nr;
+       int err = kstrtoul(buf, 0, &nr);
+
+       if (err)
+               return err;
+
+       goal->max_sample_us = nr;
+       return count;
+}
+
+static void damon_sysfs_intervals_goal_release(struct kobject *kobj)
+{
+       kfree(container_of(kobj, struct damon_sysfs_intervals_goal, kobj));
+}
+
+static struct kobj_attribute damon_sysfs_intervals_goal_access_bp_attr =
+               __ATTR_RW_MODE(access_bp, 0600);
+
+static struct kobj_attribute damon_sysfs_intervals_goal_aggrs_attr =
+               __ATTR_RW_MODE(aggrs, 0600);
+
+static struct kobj_attribute damon_sysfs_intervals_goal_min_sample_us_attr =
+               __ATTR_RW_MODE(min_sample_us, 0600);
+
+static struct kobj_attribute damon_sysfs_intervals_goal_max_sample_us_attr =
+               __ATTR_RW_MODE(max_sample_us, 0600);
+
+static struct attribute *damon_sysfs_intervals_goal_attrs[] = {
+       &damon_sysfs_intervals_goal_access_bp_attr.attr,
+       &damon_sysfs_intervals_goal_aggrs_attr.attr,
+       &damon_sysfs_intervals_goal_min_sample_us_attr.attr,
+       &damon_sysfs_intervals_goal_max_sample_us_attr.attr,
+       NULL,
+};
+ATTRIBUTE_GROUPS(damon_sysfs_intervals_goal);
+
+static const struct kobj_type damon_sysfs_intervals_goal_ktype = {
+       .release = damon_sysfs_intervals_goal_release,
+       .sysfs_ops = &kobj_sysfs_ops,
+       .default_groups = damon_sysfs_intervals_goal_groups,
+};
+
 /*
  * intervals directory
  */
@@ -417,6 +575,7 @@ struct damon_sysfs_intervals {
        unsigned long sample_us;
        unsigned long aggr_us;
        unsigned long update_us;
+       struct damon_sysfs_intervals_goal *intervals_goal;
 };
 
 static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
@@ -436,6 +595,32 @@ static struct damon_sysfs_intervals *damon_sysfs_intervals_alloc(
        return intervals;
 }
 
+static int damon_sysfs_intervals_add_dirs(struct damon_sysfs_intervals *intervals)
+{
+       struct damon_sysfs_intervals_goal *goal;
+       int err;
+
+       goal = damon_sysfs_intervals_goal_alloc(0, 0, 0, 0);
+       if (!goal)
+               return -ENOMEM;
+
+       err = kobject_init_and_add(&goal->kobj,
+                       &damon_sysfs_intervals_goal_ktype, &intervals->kobj,
+                       "intervals_goal");
+       if (err) {
+               kobject_put(&goal->kobj);
+               intervals->intervals_goal = NULL;
+               return err;
+       }
+       intervals->intervals_goal = goal;
+       return 0;
+}
+
+static void damon_sysfs_intervals_rm_dirs(struct damon_sysfs_intervals *intervals)
+{
+       kobject_put(&intervals->intervals_goal->kobj);
+}
+
 static ssize_t sample_us_show(struct kobject *kobj,
                struct kobj_attribute *attr, char *buf)
 {
@@ -569,6 +754,9 @@ static int damon_sysfs_attrs_add_dirs(struct damon_sysfs_attrs *attrs)
        err = kobject_init_and_add(&intervals->kobj,
                        &damon_sysfs_intervals_ktype, &attrs->kobj,
                        "intervals");
+       if (err)
+               goto put_intervals_out;
+       err = damon_sysfs_intervals_add_dirs(intervals);
        if (err)
                goto put_intervals_out;
        attrs->intervals = intervals;
@@ -599,6 +787,7 @@ put_intervals_out:
 static void damon_sysfs_attrs_rm_dirs(struct damon_sysfs_attrs *attrs)
 {
        kobject_put(&attrs->nr_regions_range->kobj);
+       damon_sysfs_intervals_rm_dirs(attrs->intervals);
        kobject_put(&attrs->intervals->kobj);
 }