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charset=us-ascii Content-Disposition: inline In-Reply-To: <20191022195629.GA24142@tower.DHCP.thefacebook.com> User-Agent: Mutt/1.12.2 (2019-09-21) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Oct 22, 2019 at 07:56:33PM +0000, Roman Gushchin wrote: > On Tue, Oct 22, 2019 at 10:48:00AM -0400, Johannes Weiner wrote: > > - /* Record the group's reclaim efficiency */ > > - vmpressure(sc->gfp_mask, memcg, false, > > - sc->nr_scanned - scanned, > > - sc->nr_reclaimed - reclaimed); > > - > > - } while ((memcg = mem_cgroup_iter(root, memcg, NULL))); > > + reclaimed = sc->nr_reclaimed; > > + scanned = sc->nr_scanned; > > + shrink_node_memcg(pgdat, memcg, sc); > > > > - if (reclaim_state) { > > - sc->nr_reclaimed += reclaim_state->reclaimed_slab; > > - reclaim_state->reclaimed_slab = 0; > > - } > > + shrink_slab(sc->gfp_mask, pgdat->node_id, memcg, > > + sc->priority); > > > > - /* Record the subtree's reclaim efficiency */ > > - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, > > - sc->nr_scanned - nr_scanned, > > - sc->nr_reclaimed - nr_reclaimed); > > + /* Record the group's reclaim efficiency */ > > + vmpressure(sc->gfp_mask, memcg, false, > > + sc->nr_scanned - scanned, > > + sc->nr_reclaimed - reclaimed); > > It doesn't look as a trivial change. I'd add some comments to the commit message > why it's safe to do. It's an equivalent change - it's just really misleading because the +++ lines are not the counter-part of the --- lines here! There are two vmpressure calls in this function: one against the individual cgroups, and one against the tree. The diff puts them adjacent here, but the counter-part for the --- lines is here: > > + /* Record the subtree's reclaim efficiency */ > > + vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, > > + sc->nr_scanned - nr_scanned, > > + sc->nr_reclaimed - nr_reclaimed); And the counter-part to the +++ lines is further up (beginning of the quoted diff).