On Sun, 17 May 2020 06:44:52 -0700 Shakeel Butt wrote:
> > @@ -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.
> > + }
> > +
> > + if (mem_high || swap_high) {
> > current->memcg_nr_pages_over_high += batch;
> > set_notify_resume(current);
> > break;
