From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752681AbbCDVWZ (ORCPT ); Wed, 4 Mar 2015 16:22:25 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:18755 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752391AbbCDVWY (ORCPT ); Wed, 4 Mar 2015 16:22:24 -0500 Date: Wed, 4 Mar 2015 16:21:40 -0500 From: Konrad Rzeszutek Wilk To: Bob Liu Cc: Roger Pau =?iso-8859-1?Q?Monn=E9?= , Felipe Franciosi , David Vrabel , "xen-devel@lists.xen.org" , "linux-kernel@vger.kernel.org" , "axboe@fb.com" , "hch@infradead.org" , "avanzini.arianna@gmail.com" Subject: Re: [PATCH 04/10] xen/blkfront: separate ring information to an new struct Message-ID: <20150304212140.GA18253@l.oracle.com> References: <54E4CBD1.1000802@citrix.com> <20150218173746.GF8152@l.oracle.com> <9F2C4E7DFB7839489C89757A66C5AD629EB997@AMSPEX01CL03.citrite.net> <54E544CC.4080007@oracle.com> <54E5C444.4050100@citrix.com> <54E5C59F.2060300@citrix.com> <9F2C4E7DFB7839489C89757A66C5AD629EDBBA@AMSPEX01CL03.citrite.net> <54E5E13E.9040502@citrix.com> <20150220185937.GC1749@l.oracle.com> <54F068A8.4010606@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54F068A8.4010606@oracle.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > David assertion that better performance and scalbility can be gained > > with grant table locking and TLB flush avoidance is interesting - as > > 1). The grant locking is going in Xen 4.6 but not earlier - so when running > > on older hypervisors this gives an performance benefit. > > > > 2). I have not seen any prototype TLB flush avoidance code so not know > > when that would be available. > > > > Perhaps a better choice is to do the removal of the persistence support > > when the changes in Xen hypervisor are known? > > > > With patch: [PATCH v5 0/2] gnttab: Improve scaleability, I can get > nearly the same performance as without persistence support. > > But I'm not sure about the benchmark described here: > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/block/xen-blkfront.c?id=0a8704a51f386cab7394e38ff1d66eef924d8ab8 Meaning you weren't able to do the same test? > > -- > Regards, > -Bob