From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755876Ab1BIViN (ORCPT ); Wed, 9 Feb 2011 16:38:13 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:39916 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752197Ab1BIViN (ORCPT ); Wed, 9 Feb 2011 16:38:13 -0500 Date: Wed, 9 Feb 2011 13:37:57 -0800 From: Andrew Morton To: Johannes Weiner Cc: KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , , Subject: Re: [patch 0/4] memcg: operate on page quantities internally Message-Id: <20110209133757.735b08ab.akpm@linux-foundation.org> In-Reply-To: <1297249313-23746-1-git-send-email-hannes@cmpxchg.org> References: <1297249313-23746-1-git-send-email-hannes@cmpxchg.org> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Feb 2011 12:01:49 +0100 Johannes Weiner wrote: > Hi, > > this patch set converts the memcg charge and uncharge paths to operate > on multiples of pages instead of bytes. It already was a good idea > before, but with the merge of THP we made a real mess by specifying > huge pages alternatingly in bytes or in number of regular pages. > > If I did not miss anything, this should leave only res_counter and > user-visible stuff in bytes. The ABI probably won't change, so next > up is converting res_counter to operate on page quantities. > I worry that there will be unconverted code and we'll end up adding bugs. A way to minimise the risk is to force compilation errors and warnings: rename fields and functions, reorder function arguments. Did your patches do this as much as they could have?