From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f178.google.com (mail-wi0-f178.google.com [209.85.212.178]) by kanga.kvack.org (Postfix) with ESMTP id A12956B00B8 for ; Thu, 6 Nov 2014 13:55:59 -0500 (EST) Received: by mail-wi0-f178.google.com with SMTP id bs8so2441965wib.11 for ; Thu, 06 Nov 2014 10:55:59 -0800 (PST) Received: from mail-wi0-x231.google.com (mail-wi0-x231.google.com. [2a00:1450:400c:c05::231]) by mx.google.com with ESMTPS id e2si10837382wjp.168.2014.11.06.10.55.58 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 06 Nov 2014 10:55:58 -0800 (PST) Received: by mail-wi0-f177.google.com with SMTP id ex7so2431114wid.16 for ; Thu, 06 Nov 2014 10:55:58 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> References: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> Date: Thu, 6 Nov 2014 22:55:58 +0400 Message-ID: Subject: Re: [patch 1/3] mm: embed the memcg pointer directly into struct page From: Konstantin Khlebnikov Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Vladimir Davydov , Tejun Heo , David Miller , "linux-mm@kvack.org" , cgroups@vger.kernel.org, Linux Kernel Mailing List On Sun, Nov 2, 2014 at 6:15 AM, Johannes Weiner wrote: > Memory cgroups used to have 5 per-page pointers. To allow users to > disable that amount of overhead during runtime, those pointers were > allocated in a separate array, with a translation layer between them > and struct page. > > There is now only one page pointer remaining: the memcg pointer, that > indicates which cgroup the page is associated with when charged. The > complexity of runtime allocation and the runtime translation overhead > is no longer justified to save that *potential* 0.19% of memory. With > CONFIG_SLUB, page->mem_cgroup actually sits in the doubleword padding > after the page->private member and doesn't even increase struct page, > and then this patch actually saves space. Remaining users that care > can still compile their kernels without CONFIG_MEMCG. > > text data bss dec hex filename > 8828345 1725264 983040 11536649 b00909 vmlinux.old > 8827425 1725264 966656 11519345 afc571 vmlinux.new > > Signed-off-by: Johannes Weiner Great! Never thought I'd see this. =) Acked-by: Konstantin Khlebnikov > --- > include/linux/memcontrol.h | 6 +- > include/linux/mm_types.h | 5 + > include/linux/mmzone.h | 12 -- > include/linux/page_cgroup.h | 53 -------- > init/main.c | 7 - > mm/memcontrol.c | 124 +++++------------ > mm/page_alloc.c | 2 - > mm/page_cgroup.c | 319 -------------------------------------------- > 8 files changed, 41 insertions(+), 487 deletions(-) > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index d4575a1d6e99..dafba59b31b4 100644 > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org