mm: memcontrol: Add force_reclaim to reclaim tasks' memory in memcg

[platform/kernel/linux-rpi.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 8a881ab..52ddfe8 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3643,6 +3643,36 @@ static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
        return mem_cgroup_force_empty(memcg) ?: nbytes;
 }
 
+#if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
+static int mem_cgroup_force_reclaim(struct cgroup_subsys_state *css,
+                              struct cftype *cft, u64 val)
+{
+       struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+       unsigned long nr_to_reclaim = val;
+       unsigned long total = 0;
+       int loop;
+
+       for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
+               total += try_to_free_mem_cgroup_pages(memcg, nr_to_reclaim,
+                                               GFP_KERNEL, true);
+
+               /*
+                * If nothing was reclaimed after two attempts, there
+                * may be no reclaimable pages in this hierarchy.
+                * If more than nr_to_reclaim pages were already reclaimed,
+                * finish force reclaim.
+                */
+               if (loop && (!total || total > nr_to_reclaim))
+                       break;
+       }
+
+       pr_info("%s: [Mem_reclaim] Loop: %d - Total_reclaimed: %lu - nr_to_reclaim: %lu\n",
+               __func__, loop, total, nr_to_reclaim);
+
+       return total;
+}
+#endif
+
 static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
                                     struct cftype *cft)
 {
@@ -7752,6 +7782,12 @@ static struct cftype memsw_files[] = {
                .write = mem_cgroup_reset,
                .read_u64 = mem_cgroup_read_u64,
        },
+#if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
+       {
+               .name = "force_reclaim",
+               .write_u64 = mem_cgroup_force_reclaim,
+       },
+#endif
        { },    /* terminate */
 };