From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752082Ab2I0Nwm (ORCPT ); Thu, 27 Sep 2012 09:52:42 -0400 Received: from cantor2.suse.de ([195.135.220.15]:43984 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794Ab2I0Nwl (ORCPT ); Thu, 27 Sep 2012 09:52:41 -0400 Date: Thu, 27 Sep 2012 15:52:39 +0200 From: Michal Hocko To: Glauber Costa Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org, Tejun Heo , linux-mm@kvack.org, Suleiman Souhlal , Frederic Weisbecker , Mel Gorman , David Rientjes , Christoph Lameter , Pekka Enberg , Johannes Weiner Subject: Re: [PATCH v3 07/13] mm: Allocate kernel pages to the right memcg Message-ID: <20120927135239.GF29104@dhcp22.suse.cz> References: <1347977050-29476-1-git-send-email-glommer@parallels.com> <1347977050-29476-8-git-send-email-glommer@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1347977050-29476-8-git-send-email-glommer@parallels.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 18-09-12 18:04:04, Glauber Costa wrote: > When a process tries to allocate a page with the __GFP_KMEMCG flag, the > page allocator will call the corresponding memcg functions to validate > the allocation. Tasks in the root memcg can always proceed. > > To avoid adding markers to the page - and a kmem flag that would > necessarily follow, as much as doing page_cgroup lookups for no reason, > whoever is marking its allocations with __GFP_KMEMCG flag is responsible > for telling the page allocator that this is such an allocation at > free_pages() time. This is done by the invocation of > __free_accounted_pages() and free_accounted_pages(). > > [ v2: inverted test order to avoid a memcg_get leak, > free_accounted_pages simplification ] > > Signed-off-by: Glauber Costa > CC: Christoph Lameter > CC: Pekka Enberg > CC: Michal Hocko > CC: Johannes Weiner > CC: Suleiman Souhlal > CC: Mel Gorman > Acked-by: Kamezawa Hiroyuki Acked-by: Michal Hocko Thanks! > --- > include/linux/gfp.h | 3 +++ > mm/page_alloc.c | 35 +++++++++++++++++++++++++++++++++++ > 2 files changed, 38 insertions(+) > > diff --git a/include/linux/gfp.h b/include/linux/gfp.h > index d8eae4d..029570f 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -370,6 +370,9 @@ extern void free_pages(unsigned long addr, unsigned int order); > extern void free_hot_cold_page(struct page *page, int cold); > extern void free_hot_cold_page_list(struct list_head *list, int cold); > > +extern void __free_accounted_pages(struct page *page, unsigned int order); > +extern void free_accounted_pages(unsigned long addr, unsigned int order); > + > #define __free_page(page) __free_pages((page), 0) > #define free_page(addr) free_pages((addr), 0) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index b0c5a52..897d8e2 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2573,6 +2573,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > struct page *page = NULL; > int migratetype = allocflags_to_migratetype(gfp_mask); > unsigned int cpuset_mems_cookie; > + struct mem_cgroup *memcg = NULL; > > gfp_mask &= gfp_allowed_mask; > > @@ -2591,6 +2592,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, > if (unlikely(!zonelist->_zonerefs->zone)) > return NULL; > > + /* > + * Will only have any effect when __GFP_KMEMCG is set. This is > + * verified in the (always inline) callee > + */ > + if (!memcg_kmem_newpage_charge(gfp_mask, &memcg, order)) > + return NULL; > + > retry_cpuset: > cpuset_mems_cookie = get_mems_allowed(); > > @@ -2624,6 +2632,8 @@ out: > if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) > goto retry_cpuset; > > + memcg_kmem_commit_charge(page, memcg, order); > + > return page; > } > EXPORT_SYMBOL(__alloc_pages_nodemask); > @@ -2676,6 +2686,31 @@ void free_pages(unsigned long addr, unsigned int order) > > EXPORT_SYMBOL(free_pages); > > +/* > + * __free_accounted_pages and free_accounted_pages will free pages allocated > + * with __GFP_KMEMCG. > + * > + * Those pages are accounted to a particular memcg, embedded in the > + * corresponding page_cgroup. To avoid adding a hit in the allocator to search > + * for that information only to find out that it is NULL for users who have no > + * interest in that whatsoever, we provide these functions. > + * > + * The caller knows better which flags it relies on. > + */ > +void __free_accounted_pages(struct page *page, unsigned int order) > +{ > + memcg_kmem_uncharge_page(page, order); > + __free_pages(page, order); > +} > + > +void free_accounted_pages(unsigned long addr, unsigned int order) > +{ > + if (addr != 0) { > + VM_BUG_ON(!virt_addr_valid((void *)addr)); > + __free_accounted_pages(virt_to_page((void *)addr), order); > + } > +} > + > static void *make_alloc_exact(unsigned long addr, unsigned order, size_t size) > { > if (addr) { > -- > 1.7.11.4 > > -- > To unsubscribe from this list: send the line "unsubscribe cgroups" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Michal Hocko SUSE Labs