From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f42.google.com (mail-ee0-f42.google.com [74.125.83.42]) by kanga.kvack.org (Postfix) with ESMTP id 9787C6B0039 for ; Tue, 8 Apr 2014 13:03:16 -0400 (EDT) Received: by mail-ee0-f42.google.com with SMTP id d17so927595eek.29 for ; Tue, 08 Apr 2014 10:03:16 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id y6si3586508eep.167.2014.04.08.10.03.14 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 08 Apr 2014 10:03:15 -0700 (PDT) Date: Tue, 8 Apr 2014 18:03:11 +0100 From: Mel Gorman Subject: Re: [RFC PATCH 0/5] Use an alternative to _PAGE_PROTNONE for _PAGE_NUMA v2 Message-ID: <20140408170310.GO7292@suse.de> References: <1396962570-18762-1-git-send-email-mgorman@suse.de> <53440A5D.6050301@zytor.com> <20140408164652.GL7292@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20140408164652.GL7292@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: "H. Peter Anvin" , Linux-X86 , Cyrill Gorcunov , Ingo Molnar , Steven Noonan , Rik van Riel , David Vrabel , Andrew Morton , Peter Zijlstra , Andrea Arcangeli , Dave Hansen , Srikar Dronamraju , Linux-MM , LKML On Tue, Apr 08, 2014 at 05:46:52PM +0100, Mel Gorman wrote: > On Tue, Apr 08, 2014 at 08:22:15AM -0700, Linus Torvalds wrote: > > On Tue, Apr 8, 2014 at 7:40 AM, H. Peter Anvin wrote: > > > > > > David, is your patchset going to be pushed in this merge window as expected? > > > > Apparently aiming for 3.16 right now. > > > > > > That being said, these bits are precious, and if this ends up being a > > > case where "only Xen needs another bit" once again then Xen should > > > expect to get kicked to the curb at a moment's notice. > > > > Quite frankly, I don't think it's a Xen-only issue. The code was hard > > to figure out even without the Xen issues. For example, nobody ever > > explained to me why it > > > > (a) could be the same as PROTNONE on x86 > > (b) could not be the same as PROTNONE in general > > This series exists in response to your comment > > I fundamentally think that it was a horrible horrible disaster to > make _PAGE_NUMA alias onto _PAGE_PROTNONE. > > As long as _PAGE_NUMA aliases to _PAGE_PROTNONE on x86 then the core has to > play games to take that into account and the code will be "hard to figure > out even without the Xen issues". Is what you want for _PAGE_NUMA to disappear from arch/x86 and instead use _PAGE_PROTNONE with comments explaining why and leave the core as it is? -- Mel Gorman SUSE Labs -- 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