mm/damon/sysfs-schemes: add files for setting damos_filter->sz_range

Add min and max files for damon filters to let the userspace decide the
min/max folio size to operate on.  This will be needed to decide what
folio sizes to give pa_stat for.

Link: https://lkml.kernel.org/r/20250211124437.278873-3-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 9020bc9befac4f6fe2afb2f93eecab8f06be4c41..881d00bb3a34c0af46ed4a902ed4d196d1193544 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -316,6 +316,7 @@ struct damon_sysfs_scheme_filter {
        bool allow;
        char *memcg_path;
        struct damon_addr_range addr_range;
+       struct damon_size_range sz_range;
        int target_idx;
 };
 
@@ -474,6 +475,44 @@ static ssize_t addr_end_store(struct kobject *kobj,
        return err ? err : count;
 }
 
+static ssize_t min_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, "%lu\n", filter->sz_range.min);
+}
+
+static ssize_t min_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);
+       int err = kstrtoul(buf, 0, &filter->sz_range.min);
+
+       return err ? err : count;
+}
+
+static ssize_t max_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, "%lu\n", filter->sz_range.max);
+}
+
+static ssize_t max_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);
+       int err = kstrtoul(buf, 0, &filter->sz_range.max);
+
+       return err ? err : count;
+}
+
 static ssize_t damon_target_idx_show(struct kobject *kobj,
                struct kobj_attribute *attr, char *buf)
 {
@@ -520,6 +559,12 @@ static struct kobj_attribute damon_sysfs_scheme_filter_addr_start_attr =
 static struct kobj_attribute damon_sysfs_scheme_filter_addr_end_attr =
                __ATTR_RW_MODE(addr_end, 0600);
 
+static struct kobj_attribute damon_sysfs_scheme_filter_min_attr =
+               __ATTR_RW_MODE(min, 0600);
+
+static struct kobj_attribute damon_sysfs_scheme_filter_max_attr =
+               __ATTR_RW_MODE(max, 0600);
+
 static struct kobj_attribute damon_sysfs_scheme_filter_damon_target_idx_attr =
                __ATTR_RW_MODE(damon_target_idx, 0600);
 
@@ -530,6 +575,8 @@ static struct attribute *damon_sysfs_scheme_filter_attrs[] = {
        &damon_sysfs_scheme_filter_memcg_path_attr.attr,
        &damon_sysfs_scheme_filter_addr_start_attr.attr,
        &damon_sysfs_scheme_filter_addr_end_attr.attr,
+       &damon_sysfs_scheme_filter_min_attr.attr,
+       &damon_sysfs_scheme_filter_max_attr.attr,
        &damon_sysfs_scheme_filter_damon_target_idx_attr.attr,
        NULL,
 };
@@ -1954,6 +2001,13 @@ static int damon_sysfs_add_scheme_filters(struct damos *scheme,
                        filter->addr_range = sysfs_filter->addr_range;
                } else if (filter->type == DAMOS_FILTER_TYPE_TARGET) {
                        filter->target_idx = sysfs_filter->target_idx;
+               } else if (filter->type == DAMOS_FILTER_TYPE_HUGEPAGE_SIZE) {
+                       if (sysfs_filter->sz_range.min >
+                                       sysfs_filter->sz_range.max) {
+                               damos_destroy_filter(filter);
+                               return -EINVAL;
+                       }
+                       filter->sz_range = sysfs_filter->sz_range;
                }
 
                damos_add_filter(scheme, filter);