From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 8B6926B00DD for ; Tue, 4 Nov 2014 03:37:25 -0500 (EST) Received: by mail-pa0-f50.google.com with SMTP id eu11so14119834pac.9 for ; Tue, 04 Nov 2014 00:37:25 -0800 (PST) Received: from fgwmail6.fujitsu.co.jp (fgwmail6.fujitsu.co.jp. [192.51.44.36]) by mx.google.com with ESMTPS id o8si17516169pds.34.2014.11.04.00.37.23 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 04 Nov 2014 00:37:24 -0800 (PST) Received: from kw-mxoi2.gw.nic.fujitsu.com (unknown [10.0.237.143]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 8F9C43EE0B6 for ; Tue, 4 Nov 2014 17:37:22 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by kw-mxoi2.gw.nic.fujitsu.com (Postfix) with ESMTP id 9C8A5AC048D for ; Tue, 4 Nov 2014 17:37:21 +0900 (JST) Received: from g01jpfmpwkw01.exch.g01.fujitsu.local (g01jpfmpwkw01.exch.g01.fujitsu.local [10.0.193.38]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 3C8321DB8041 for ; Tue, 4 Nov 2014 17:37:21 +0900 (JST) Message-ID: <54589017.9060604@jp.fujitsu.com> Date: Tue, 4 Nov 2014 17:36:39 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [patch 1/3] mm: embed the memcg pointer directly into struct page References: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> In-Reply-To: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner , Andrew Morton Cc: Michal Hocko , Vladimir Davydov , Tejun Heo , David Miller , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org (2014/11/02 12:15), 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 > --- > 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(-) > Great! Acked-by: KAMEZAWA Hiroyuki BTW, init/Kconfig comments shouldn't be updated ? (I'm sorry if it has been updated since your latest fix.) -- 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