Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753789AbaKCVHR (ORCPT ); Mon, 3 Nov 2014 16:07:17 -0500 Received: from mta-out1.inet.fi ([62.71.2.234]:56354 "EHLO jenni2.inet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751934AbaKCVHP (ORCPT ); Mon, 3 Nov 2014 16:07:15 -0500 Date: Mon, 3 Nov 2014 23:06:07 +0200 From: "Kirill A. Shutemov" To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Vladimir Davydov , Tejun Heo , David Miller , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/3] mm: embed the memcg pointer directly into struct page Message-ID: <20141103210607.GA24091@node.dhcp.inet.fi> References: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414898156-4741-1-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 01, 2014 at 11:15:54PM -0400, 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. How much do you win by the change? -- Kirill A. Shutemov -- 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/