mm/damon/sysfs: reuse damon_set_regions() for regions setting

'damon_set_regions()' is general enough so that it can also be used for
only creating regions.  This commit makes DAMON sysfs interface to reuse
the function rather keeping two implementations for a same purpose.

Link: https://lkml.kernel.org/r/20220429160606.127307-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index a9d4f93..b85efe2 100644 (file)
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -2096,28 +2096,31 @@ static void damon_sysfs_destroy_targets(struct damon_ctx *ctx)
 static int damon_sysfs_set_regions(struct damon_target *t,
                struct damon_sysfs_regions *sysfs_regions)
 {
-       int i;
+       struct damon_addr_range *ranges = kmalloc_array(sysfs_regions->nr,
+                       sizeof(*ranges), GFP_KERNEL | __GFP_NOWARN);
+       int i, err = -EINVAL;
 
+       if (!ranges)
+               return -ENOMEM;
        for (i = 0; i < sysfs_regions->nr; i++) {
                struct damon_sysfs_region *sys_region =
                        sysfs_regions->regions_arr[i];
-               struct damon_region *prev, *r;
 
                if (sys_region->start > sys_region->end)
-                       return -EINVAL;
-               r = damon_new_region(sys_region->start, sys_region->end);
-               if (!r)
-                       return -ENOMEM;
-               damon_add_region(r, t);
-               if (damon_nr_regions(t) > 1) {
-                       prev = damon_prev_region(r);
-                       if (prev->ar.end > r->ar.start) {
-                               damon_destroy_region(r, t);
-                               return -EINVAL;
-                       }
-               }
+                       goto out;
+
+               ranges[i].start = sys_region->start;
+               ranges[i].end = sys_region->end;
+               if (i == 0)
+                       continue;
+               if (ranges[i - 1].end > ranges[i].start)
+                       goto out;
        }
-       return 0;
+       err = damon_set_regions(t, ranges, sysfs_regions->nr);
+out:
+       kfree(ranges);
+       return err;
+
 }
 
 static int damon_sysfs_add_target(struct damon_sysfs_target *sys_target,