mm/damon/sysfs-schemes: support address range type DAMOS filter

Extend DAMON sysfs interface to support address range based DAMOS filters,
by adding a special keyword for the filter/<N>/type file, namely 'addr',
and two files under filter/<N>/ for specifying the start and the end
addresses of the range, namely 'addr_start' and 'addr_end'.

Link: https://lkml.kernel.org/r/20230802214312.110532-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.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 9a015079f3a46fd9ea1c968401f3d8250e028d8c..03ddba3e216d13ade2600111dc3118424913c0c2 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -282,6 +282,7 @@ struct damon_sysfs_scheme_filter {
        enum damos_filter_type type;
        bool matching;
        char *memcg_path;
+       struct damon_addr_range addr_range;
 };
 
 static struct damon_sysfs_scheme_filter *damon_sysfs_scheme_filter_alloc(void)
@@ -293,6 +294,7 @@ static struct damon_sysfs_scheme_filter *damon_sysfs_scheme_filter_alloc(void)
 static const char * const damon_sysfs_scheme_filter_type_strs[] = {
        "anon",
        "memcg",
+       "addr",
 };
 
 static ssize_t type_show(struct kobject *kobj,
@@ -373,6 +375,44 @@ static ssize_t memcg_path_store(struct kobject *kobj,
        return count;
 }
 
+static ssize_t addr_start_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->addr_range.start);
+}
+
+static ssize_t addr_start_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->addr_range.start);
+
+       return err ? err : count;
+}
+
+static ssize_t addr_end_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->addr_range.end);
+}
+
+static ssize_t addr_end_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->addr_range.end);
+
+       return err ? err : count;
+}
+
 static void damon_sysfs_scheme_filter_release(struct kobject *kobj)
 {
        struct damon_sysfs_scheme_filter *filter = container_of(kobj,
@@ -391,10 +431,18 @@ static struct kobj_attribute damon_sysfs_scheme_filter_matching_attr =
 static struct kobj_attribute damon_sysfs_scheme_filter_memcg_path_attr =
                __ATTR_RW_MODE(memcg_path, 0600);
 
+static struct kobj_attribute damon_sysfs_scheme_filter_addr_start_attr =
+               __ATTR_RW_MODE(addr_start, 0600);
+
+static struct kobj_attribute damon_sysfs_scheme_filter_addr_end_attr =
+               __ATTR_RW_MODE(addr_end, 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,
+       &damon_sysfs_scheme_filter_addr_start_attr.attr,
+       &damon_sysfs_scheme_filter_addr_end_attr.attr,
        NULL,
 };
 ATTRIBUTE_GROUPS(damon_sysfs_scheme_filter);
@@ -1484,7 +1532,15 @@ static int damon_sysfs_set_scheme_filters(struct damos *scheme,
                                damos_destroy_filter(filter);
                                return err;
                        }
+               } else if (filter->type == DAMOS_FILTER_TYPE_ADDR) {
+                       if (sysfs_filter->addr_range.end <
+                                       sysfs_filter->addr_range.start) {
+                               damos_destroy_filter(filter);
+                               return -EINVAL;
+                       }
+                       filter->addr_range = sysfs_filter->addr_range;
                }
+
                damos_add_filter(scheme, filter);
        }
        return 0;