Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756297AbaDHJbj (ORCPT ); Tue, 8 Apr 2014 05:31:39 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:41518 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756065AbaDHJbi (ORCPT ); Tue, 8 Apr 2014 05:31:38 -0400 X-IronPort-AV: E=Sophos;i="4.97,816,1389744000"; d="scan'208";a="117796899" Message-ID: <5343C1F6.4090600@citrix.com> Date: Tue, 8 Apr 2014 10:31:34 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20121215 Iceowl/1.0b1 Icedove/3.0.11 MIME-Version: 1.0 To: Cyrill Gorcunov CC: "H. Peter Anvin" , Mel Gorman , Linus Torvalds , Ingo Molnar , Steven Noonan , Rik van Riel , Andrew Morton , Peter Zijlstra , Andrea Arcangeli , Linux-MM , Linux-X86 , LKML , Pavel Emelyanov Subject: Re: [PATCH 2/3] x86: Define _PAGE_NUMA with unused physical address bits PMD and PTE levels References: <1396883443-11696-1-git-send-email-mgorman@suse.de> <1396883443-11696-3-git-send-email-mgorman@suse.de> <5342C517.2020305@citrix.com> <20140407154935.GD7292@suse.de> <20140407161910.GJ1444@moon> <20140407182854.GH7292@suse.de> <5342FC0E.9080701@zytor.com> <20140407193646.GC23983@moon> In-Reply-To: <20140407193646.GC23983@moon> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.76] X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/04/14 20:36, Cyrill Gorcunov wrote: > On Mon, Apr 07, 2014 at 12:27:10PM -0700, H. Peter Anvin wrote: >> On 04/07/2014 11:28 AM, Mel Gorman wrote: >>> >>> I had considered the soft-dirty tracking usage of the same bit. I thought I'd >>> be able to swizzle around it or a further worst case of having soft-dirty and >>> automatic NUMA balancing mutually exclusive. Unfortunately upon examination >>> it's not obvious how to have both of them share a bit and I suspect any >>> attempt to will break CRIU. In my current tree, NUMA_BALANCING cannot be >>> set if MEM_SOFT_DIRTY which is not particularly satisfactory. Next on the >>> list is examining if _PAGE_BIT_IOMAP can be used. >> >> Didn't we smoke the last user of _PAGE_BIT_IOMAP? Not yet. A last minute regression with mapping of I/O regions from userspace was found so I had to drop the series from 3.15. It should be back for 3.16. > Seems so, at least for non-kernel pages (not considering this bit references in > xen code, which i simply don't know but i guess it's used for kernel pages only). Xen uses it for all I/O mappings, both kernel and for userspace. David -- 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/