Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753403Ab2HMIFa (ORCPT ); Mon, 13 Aug 2012 04:05:30 -0400 Received: from mx2.parallels.com ([64.131.90.16]:49881 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752912Ab2HMIF0 (ORCPT ); Mon, 13 Aug 2012 04:05:26 -0400 Message-ID: <5028B488.6060201@parallels.com> Date: Mon, 13 Aug 2012 12:02:16 +0400 From: Glauber Costa User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Greg Thelen CC: , , , , Michal Hocko , Johannes Weiner , Andrew Morton , , Christoph Lameter , David Rientjes , Pekka Enberg , Pekka Enberg , Suleiman Souhlal Subject: Re: [PATCH v2 07/11] mm: Allocate kernel pages to the right memcg References: <1344517279-30646-1-git-send-email-glommer@parallels.com> <1344517279-30646-8-git-send-email-glommer@parallels.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4579 Lines: 115 On 08/10/2012 09:36 PM, Greg Thelen wrote: > On Thu, Aug 09 2012, 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(). >> >> Signed-off-by: Glauber Costa >> CC: Christoph Lameter >> CC: Pekka Enberg >> CC: Michal Hocko >> CC: Kamezawa Hiroyuki >> CC: Johannes Weiner >> CC: Suleiman Souhlal >> --- >> include/linux/gfp.h | 3 +++ >> mm/page_alloc.c | 38 ++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 41 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 b956cec..da341dc 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -2532,6 +2532,7 @@ __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; >> + void *handle = NULL; >> >> gfp_mask &= gfp_allowed_mask; >> >> @@ -2543,6 +2544,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, >> return NULL; >> >> /* >> + * Will only have any effect when __GFP_KMEMCG is set. >> + * This is verified in the (always inline) callee >> + */ >> + if (!memcg_kmem_new_page(gfp_mask, &handle, order)) >> + return NULL; >> + >> + /* >> * Check the zones suitable for the gfp_mask contain at least one >> * valid zone. It's possible to have an empty zonelist as a result >> * of GFP_THISNODE and a memoryless node >> @@ -2583,6 +2591,8 @@ out: >> if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page)) >> goto retry_cpuset; >> >> + memcg_kmem_commit_page(page, handle, order); >> + >> return page; >> } >> EXPORT_SYMBOL(__alloc_pages_nodemask); >> @@ -2635,6 +2645,34 @@ 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_free_page(page, order); >> + __free_pages(page, order); >> +} >> +EXPORT_SYMBOL(__free_accounted_pages); >> + >> +void free_accounted_pages(unsigned long addr, unsigned int order) >> +{ >> + if (addr != 0) { >> + VM_BUG_ON(!virt_addr_valid((void *)addr)); >> + memcg_kmem_free_page(virt_to_page((void *)addr), order); >> + __free_pages(virt_to_page((void *)addr), order); > > Nit. Is there any reason not to replace the above two lines with: > __free_accounted_pages(virt_to_page((void *)addr), order); > Not any particular reason. If people prefer it this way, I can do that with no problems. -- 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/