From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: [PATCH][RFC]Provide fast write emulation path to release shadow lock Date: Tue, 22 Jan 2008 09:26:08 +0000 Message-ID: <20080122092608.GA12891@york.uk.xensource.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Tian, Kevin" Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org At 10:20 +0800 on 22 Jan (1200997253), Tian, Kevin wrote: > We also did series of tests on 32/32pae/32e: (host is 32e) > 32 32pae 32e > ----Linux---- > kernel build +1% +0.86% +1.9% > Specjbb +0.9% +1.61% +0.32% > > ----XP---- > Sysbench N/A -0.05% -0.32%(*) > > * Sysbench score is not very stable on 32e guest, with up > to 6% variation observed in 5 rounds running. 32pae is > stable. 32 XP image was unfortunately corrupted at test > cycle, so not test yet. Don't want to hold here from getting > early comments. :-) > > I thought the performance gain should be straightforward > with this patch, and thus would like to know comment > like: > - Is it a right direction? Looks good to me! > - Is there anything wrong or missed in patch? Nothing fundamental that I can see by reading through it. One thing I'd change is to avoid introducing "vfn": a virtual address >> PAGE_SIZE is just a "page number". > - Any more benchmarks should we test? Anything and everything. :) Specially multi-vcpu mixed operations (e.g. kernel compile + ltp + network traffic) while doing live migrate. Even when they look as clean as this one, changes in the shadow fault handler tend to chase out implicit/forgotten assumptions. Cheers, Tim. -- Tim Deegan Principal Software Engineer, Citrix Systems (R&D) Ltd. [Company #02300071, SL9 0DZ, UK.]