Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755274AbaJVPxb (ORCPT ); Wed, 22 Oct 2014 11:53:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43023 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755039AbaJVPqH (ORCPT ); Wed, 22 Oct 2014 11:46:07 -0400 Date: Wed, 22 Oct 2014 17:46:06 +0200 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Hugh Dickins , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 2/4] mm: memcontrol: remove unnecessary PCG_MEMSW memory+swap charge flag Message-ID: <20141022154606.GE30802@dhcp22.suse.cz> References: <1413818532-11042-1-git-send-email-hannes@cmpxchg.org> <1413818532-11042-3-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413818532-11042-3-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 20-10-14 11:22:10, Johannes Weiner wrote: > Now that mem_cgroup_swapout() fully uncharges the page, every page > that is still in use when reaching mem_cgroup_uncharge() is known to > carry both the memory and the memory+swap charge. Simplify the > uncharge path and remove the PCG_MEMSW page flag accordingly. > > Signed-off-by: Johannes Weiner Looks good Acked-by: Michal Hocko > --- > include/linux/page_cgroup.h | 1 - > mm/memcontrol.c | 34 ++++++++++++---------------------- > 2 files changed, 12 insertions(+), 23 deletions(-) > > diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h > index 5c831f1eca79..da62ee2be28b 100644 > --- a/include/linux/page_cgroup.h > +++ b/include/linux/page_cgroup.h > @@ -5,7 +5,6 @@ enum { > /* flags for mem_cgroup */ > PCG_USED = 0x01, /* This page is charged to a memcg */ > PCG_MEM = 0x02, /* This page holds a memory charge */ > - PCG_MEMSW = 0x04, /* This page holds a memory+swap charge */ > }; > > struct pglist_data; > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 7709f17347f3..9bab35fc3e9e 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2606,7 +2606,7 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg, > * have the page locked > */ > pc->mem_cgroup = memcg; > - pc->flags = PCG_USED | PCG_MEM | (do_swap_account ? PCG_MEMSW : 0); > + pc->flags = PCG_USED | PCG_MEM; > > if (lrucare) > unlock_page_lru(page, isolated); > @@ -5815,7 +5815,6 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) > if (!PageCgroupUsed(pc)) > return; > > - VM_BUG_ON_PAGE(!(pc->flags & PCG_MEMSW), page); > memcg = pc->mem_cgroup; > > oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg)); > @@ -6010,17 +6009,16 @@ void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg) > } > > static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, > - unsigned long nr_mem, unsigned long nr_memsw, > unsigned long nr_anon, unsigned long nr_file, > unsigned long nr_huge, struct page *dummy_page) > { > + unsigned long nr_pages = nr_anon + nr_file; > unsigned long flags; > > if (!mem_cgroup_is_root(memcg)) { > - if (nr_mem) > - page_counter_uncharge(&memcg->memory, nr_mem); > - if (nr_memsw) > - page_counter_uncharge(&memcg->memsw, nr_memsw); > + page_counter_uncharge(&memcg->memory, nr_pages); > + if (do_swap_account) > + page_counter_uncharge(&memcg->memsw, nr_pages); > memcg_oom_recover(memcg); > } > > @@ -6029,23 +6027,21 @@ static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout, > __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file); > __this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge); > __this_cpu_add(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT], pgpgout); > - __this_cpu_add(memcg->stat->nr_page_events, nr_anon + nr_file); > + __this_cpu_add(memcg->stat->nr_page_events, nr_pages); > memcg_check_events(memcg, dummy_page); > local_irq_restore(flags); > > if (!mem_cgroup_is_root(memcg)) > - css_put_many(&memcg->css, max(nr_mem, nr_memsw)); > + css_put_many(&memcg->css, nr_pages); > } > > static void uncharge_list(struct list_head *page_list) > { > struct mem_cgroup *memcg = NULL; > - unsigned long nr_memsw = 0; > unsigned long nr_anon = 0; > unsigned long nr_file = 0; > unsigned long nr_huge = 0; > unsigned long pgpgout = 0; > - unsigned long nr_mem = 0; > struct list_head *next; > struct page *page; > > @@ -6072,10 +6068,9 @@ static void uncharge_list(struct list_head *page_list) > > if (memcg != pc->mem_cgroup) { > if (memcg) { > - uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw, > - nr_anon, nr_file, nr_huge, page); > - pgpgout = nr_mem = nr_memsw = 0; > - nr_anon = nr_file = nr_huge = 0; > + uncharge_batch(memcg, pgpgout, nr_anon, nr_file, > + nr_huge, page); > + pgpgout = nr_anon = nr_file = nr_huge = 0; > } > memcg = pc->mem_cgroup; > } > @@ -6091,18 +6086,14 @@ static void uncharge_list(struct list_head *page_list) > else > nr_file += nr_pages; > > - if (pc->flags & PCG_MEM) > - nr_mem += nr_pages; > - if (pc->flags & PCG_MEMSW) > - nr_memsw += nr_pages; > pc->flags = 0; > > pgpgout++; > } while (next != page_list); > > if (memcg) > - uncharge_batch(memcg, pgpgout, nr_mem, nr_memsw, > - nr_anon, nr_file, nr_huge, page); > + uncharge_batch(memcg, pgpgout, nr_anon, nr_file, > + nr_huge, page); > } > > /** > @@ -6187,7 +6178,6 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage, > return; > > VM_BUG_ON_PAGE(!(pc->flags & PCG_MEM), oldpage); > - VM_BUG_ON_PAGE(do_swap_account && !(pc->flags & PCG_MEMSW), oldpage); > > if (lrucare) > lock_page_lru(oldpage, &isolated); > -- > 2.1.2 > -- Michal Hocko SUSE Labs -- 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/