From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753150AbaAXOo0 (ORCPT ); Fri, 24 Jan 2014 09:44:26 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:22543 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752818AbaAXOoY (ORCPT ); Fri, 24 Jan 2014 09:44:24 -0500 X-IronPort-AV: E=Sophos;i="4.95,713,1384300800"; d="scan'208";a="94151539" Message-ID: <52E27C45.4040706@citrix.com> Date: Fri, 24 Jan 2014 14:44:21 +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: Konrad Rzeszutek Wilk CC: Zoltan Kiss , Stefano Stabellini , , , , , , , Subject: Re: [Xen-devel] [PATCH v5] xen/grant-table: Avoid m2p_override during mapping References: <1390482430-9168-1-git-send-email-zoltan.kiss@citrix.com> <20140124143711.GB12946@phenom.dumpdata.com> In-Reply-To: <20140124143711.GB12946@phenom.dumpdata.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 24/01/14 14:37, Konrad Rzeszutek Wilk wrote: > On Thu, Jan 23, 2014 at 01:07:10PM +0000, 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 >> >> It also removes a stray space from page.h and change ret to 0 if >> XENFEAT_auto_translated_physmap, as that is the only possible return value >> there. >> >> 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 >> >> v5: >> - change return value handling in __gnttab_[un]map_refs >> - remove a stray space in page.h >> - add detail why ret = 0 now at some places >> >> Signed-off-by: Zoltan Kiss >> Suggested-by: David Vrabel > > It looks OK to me and while it is not a bug-fix I think it should > go for v3.14 - as it _should_ improve the backends. > > David or Boris; Stefano, please Ack/Nack it. Reviewed-by: David Vrabel David