From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759625Ab2CMVdV (ORCPT ); Tue, 13 Mar 2012 17:33:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:49261 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853Ab2CMVdS (ORCPT ); Tue, 13 Mar 2012 17:33:18 -0400 Date: Tue, 13 Mar 2012 14:33:16 -0700 From: Andrew Morton To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, mgorman@suse.de, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, aarcange@redhat.com, mhocko@suse.cz, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH -V3 2/8] memcg: Add HugeTLB extension Message-Id: <20120313143316.0ef74d0e.akpm@linux-foundation.org> In-Reply-To: <1331622432-24683-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1331622432-24683-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1331622432-24683-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> 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 Tue, 13 Mar 2012 12:37:06 +0530 "Aneesh Kumar K.V" wrote: > +static int mem_cgroup_hugetlb_usage(struct mem_cgroup *memcg) > +{ > + int idx; > + for (idx = 0; idx < hugetlb_max_hstate; idx++) { > + if (memcg->hugepage[idx].usage > 0) > + return memcg->hugepage[idx].usage; > + } > + return 0; > +} Please document the function? Had you done this, I might have been able to work out why the function bales out on the first used hugepage size, but I can't :( This could have used for_each_hstate(), had that macro been better designed (or updated). Upon return this function coerces an unsigned long long into an "int". We decided last week that more than 2^32 hugepages was not inconceivable, so I guess that's a bug.