Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753100Ab2EaGuX (ORCPT ); Thu, 31 May 2012 02:50:23 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:62131 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751571Ab2EaGuU (ORCPT ); Thu, 31 May 2012 02:50:20 -0400 Date: Wed, 30 May 2012 23:50:18 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: "Aneesh Kumar K.V" cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, mhocko@suse.cz, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Andrea Arcangeli Subject: Re: [PATCH -V7 02/14] hugetlbfs: don't use ERR_PTR with VM_FAULT* values In-Reply-To: <20120531054533.GE24855@skywalker.linux.vnet.ibm.com> Message-ID: References: <1338388739-22919-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1338388739-22919-3-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120531054533.GE24855@skywalker.linux.vnet.ibm.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1141 Lines: 23 On Thu, 31 May 2012, Aneesh Kumar K.V wrote: > > Yeah, but is there a reason for using VM_FAULT_HWPOISON_LARGE_MASK since > > that's the only VM_FAULT_* value that is greater than MAX_ERRNO? The rest > > of your patch set doesn't require this, so I think this change should just > > be dropped. (And PTR_ERR() still returns long, this wasn't fixed from my > > original review.) > > > > The changes was done as per Andrew's request so that we don't have such hidden > dependencies on the values of VM_FAULT_*. Yes it can be a seperate patch from > the patchset. I have changed int to long as per your review. > I think it confuscates the code, can't we just add something like BUILD_BUG_ON() to ensure that PTR_ERR() never uses values that are outside the bounds of MAX_ERRNO so we'll catch these at compile time if mm/hugetlb.c or anything else is ever extended to use such values? -- 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/