Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754760Ab3HAKVh (ORCPT ); Thu, 1 Aug 2013 06:21:37 -0400 Received: from smtp.eu.citrix.com ([46.33.159.39]:33950 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751177Ab3HAKVg (ORCPT ); Thu, 1 Aug 2013 06:21:36 -0400 X-IronPort-AV: E=Sophos;i="4.89,793,1367971200"; d="scan'208";a="7357621" Message-ID: <51FA36AC.1090609@citrix.com> Date: Thu, 1 Aug 2013 12:21:32 +0200 From: =?UTF-8?B?Um9nZXIgUGF1IE1vbm7DqQ==?= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: David Vrabel CC: , , Stefano Stabellini Subject: Re: [Xen-devel] [PATCH RFC] p2m: use GNTTABOP_unmap_and_duplicate if available References: <1375286855-4861-1-git-send-email-roger.pau@citrix.com> <51FA302B.90106@citrix.com> In-Reply-To: <51FA302B.90106@citrix.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.30.203.1] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1199 Lines: 33 On 01/08/13 11:53, David Vrabel wrote: > On 31/07/13 17:07, Roger Pau Monne wrote: >> The new GNTTABOP_unmap_and_duplicate operation doesn't zero the >> mapping passed in new_addr, allowing us to perform batch unmaps in p2m >> code without requiring the use of a multicall. > > Thanks. This looks like it should be a good performance improvement for > userspace-based backends. Do you have any performance measurements for > (e.g.) qemu's disk backend? Not yet, I might be able to get some initial performance measurements tomorrow. > >> --- a/arch/x86/xen/p2m.c >> +++ b/arch/x86/xen/p2m.c > [...] >> +int m2p_remove_override_batch(struct page **pages, >> + struct gnttab_map_grant_ref *kmap_ops, int count) >> +{ > > Is it possible to refactor this function and > m2p_remove_override_single() to share some common helper functions? Yes, I will split those common parts into inline functions and share them between both implementations. Roger. -- 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/