Re: [PATCH mm v3 3/3] mm: automatically penalize tasks with high swap use

On Sun, 17 May 2020 06:44:52 -0700 Shakeel Butt wrote:

quoted

@@ -2583,12 +2606,23 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
         * reclaim, the cost of mismatch is negligible.
         */
        do {
-               if (page_counter_read(&memcg->memory) > READ_ONCE(memcg->high)) {
-                       /* Don't bother a random interrupted task */
-                       if (in_interrupt()) {
+               bool mem_high, swap_high;
+
+               mem_high = page_counter_read(&memcg->memory) >
+                       READ_ONCE(memcg->high);
+               swap_high = page_counter_read(&memcg->swap) >
+                       READ_ONCE(memcg->swap_high);
+
+               /* Don't bother a random interrupted task */
+               if (in_interrupt()) {
+                       if (mem_high) {
                                schedule_work(&memcg->high_work);
                                break;
                        }
+                       continue;  

break?

On a closer look I think continue is correct. In irq we only care 
about mem_high, because there's nothing we can do in a work context 
to penalize swap. So the loop is shortened.

quoted

+               }
+
+               if (mem_high || swap_high) {
                        current->memcg_nr_pages_over_high += batch;
                        set_notify_resume(current);
                        break;