Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755223AbaAVK6J (ORCPT ); Wed, 22 Jan 2014 05:58:09 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:1098 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751773AbaAVK6F (ORCPT ); Wed, 22 Jan 2014 05:58:05 -0500 X-IronPort-AV: E=Sophos;i="4.95,699,1384300800"; d="scan'208";a="93196688" Message-ID: <52DFA438.6050103@citrix.com> Date: Wed, 22 Jan 2014 10:58:00 +0000 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: Zoltan Kiss CC: , , , , , , Stefano Stabellini Subject: Re: [Xen-devel] [PATCH v4] xen/grant-table: Avoid m2p_override during mapping References: <1390335755-29328-1-git-send-email-zoltan.kiss@citrix.com> In-Reply-To: <1390335755-29328-1-git-send-email-zoltan.kiss@citrix.com> 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 21/01/14 20:22, Zoltan Kiss wrote: > The grant mapping API does m2p_override unnecessarily: only gntdev needs it, > for blkback and future netback patches it just cause a lock contention, as > those pages never go to userspace. Therefore this series does the following: > - the original functions were renamed to __gnttab_[un]map_refs, with a new > parameter m2p_override > - based on m2p_override either they follow the original behaviour, or just set > the private flag and call set_phys_to_machine > - gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs with > m2p_override false > - a new function gnttab_[un]map_refs_userspace provides the old behaviour > > v2: > - move the storing of the old mfn in page->index to gnttab_map_refs > - move the function header update to a separate patch > > v3: > - a new approach to retain old behaviour where it needed > - squash the patches into one > > v4: > - move out the common bits from m2p* functions, and pass pfn/mfn as parameter > - clear page->private before doing anything with the page, so m2p_find_override > won't race with this I would prune this version information out of the commit message. > Signed-off-by: Zoltan Kiss > Suggested-by: David Vrabel Reviewed-by: David Vrabel But I think this needs Stefano's ack. It would be useful to get this into 3.14 if possible. 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/