Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935082AbbKTNK5 (ORCPT ); Fri, 20 Nov 2015 08:10:57 -0500 Received: from mx2.parallels.com ([199.115.105.18]:41476 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751457AbbKTNKz (ORCPT ); Fri, 20 Nov 2015 08:10:55 -0500 Date: Fri, 20 Nov 2015 16:10:33 +0300 From: Vladimir Davydov To: Johannes Weiner CC: David Miller , Andrew Morton , Tejun Heo , Michal Hocko , , , , , Subject: Re: [PATCH 13/14] mm: memcontrol: account socket memory in unified hierarchy memory controller Message-ID: <20151120131033.GF31308@esperanza> References: <1447371693-25143-1-git-send-email-hannes@cmpxchg.org> <1447371693-25143-14-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1447371693-25143-14-git-send-email-hannes@cmpxchg.org> X-ClientProxiedBy: US-EXCH.sw.swsoft.com (10.255.249.47) To US-EXCH2.sw.swsoft.com (10.255.249.46) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2319 Lines: 76 On Thu, Nov 12, 2015 at 06:41:32PM -0500, Johannes Weiner wrote: ... > @@ -5514,16 +5550,43 @@ void sock_release_memcg(struct sock *sk) > */ > bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) > { > + unsigned int batch = max(CHARGE_BATCH, nr_pages); > struct page_counter *counter; > + bool force = false; > > - if (page_counter_try_charge(&memcg->tcp_mem.memory_allocated, > - nr_pages, &counter)) { > - memcg->tcp_mem.memory_pressure = 0; > +#ifdef CONFIG_MEMCG_KMEM > + if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) { > + if (page_counter_try_charge(&memcg->tcp_mem.memory_allocated, > + nr_pages, &counter)) { > + memcg->tcp_mem.memory_pressure = 0; > + return true; > + } > + page_counter_charge(&memcg->tcp_mem.memory_allocated, nr_pages); > + memcg->tcp_mem.memory_pressure = 1; > + return false; > + } > +#endif > + if (consume_stock(memcg, nr_pages)) > return true; > +retry: > + if (page_counter_try_charge(&memcg->memory, batch, &counter)) > + goto done; > + > + if (batch > nr_pages) { > + batch = nr_pages; > + goto retry; > } > - page_counter_charge(&memcg->tcp_mem.memory_allocated, nr_pages); > - memcg->tcp_mem.memory_pressure = 1; > - return false; > + > + page_counter_charge(&memcg->memory, batch); > + force = true; > +done: > + css_get_many(&memcg->css, batch); Is there any point to get css reference per each charged page? For kmem it is absolutely necessary, because dangling slabs must block destruction of memcg's kmem caches, which are destroyed on css_free. But for sockets there's no such problem: memcg will be destroyed only after all sockets are destroyed and therefore uncharged (since sock_update_memcg pins css). > + if (batch > nr_pages) > + refill_stock(memcg, batch - nr_pages); > + > + schedule_work(&memcg->socket_work); I think it's suboptimal to schedule the work even if we are below the high threshold. BTW why do we need this work at all? Why is reclaim_high called from task_work not enough? Thanks, Vladimir > + > + return !force; > } > > /** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/