From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: Ping: [PATCH 0/4] HVM: produce better binary code Date: Wed, 4 Sep 2013 17:16:44 +0100 Message-ID: <52275CEC.7000308@citrix.com> References: <521786A002000078000EE064@nat28.tlf.novell.com> <5227223902000078000F048E@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VHFlA-000558-Bh for xen-devel@lists.xenproject.org; Wed, 04 Sep 2013 16:16:48 +0000 In-Reply-To: <5227223902000078000F048E@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: suravee.suthikulpanit@amd.com, Jacob Shin , Eddie Dong , Tim Deegan , Jun Nakajima , xen-devel , Boris Ostrovsky List-Id: xen-devel@lists.xenproject.org On 04/09/13 11:06, Jan Beulich wrote: >>>> On 23.08.13 at 15:58, "Jan Beulich" wrote: > While I got two reviews meanwhile for this series (thanks Andrew > and Tim!), ack-s from the maintainers are still missing: > >> 1: VMX: streamline entry.S code >> 2: VMX: move various uses of UD2 out of fast paths >> 3: VMX: use proper instruction mnemonics if assembler supports them > Jun, Eddie? (Yes, there had been a couple of revisions to patches > 2 and 3, but even their sending was now more than a week ago.) > >> 4: SVM: streamline entry.S code > Suravee, Boris, Jacob? > > I'm going to wait a for perhaps another day or two, and will assume > silent agreement if I don't hear otherwise. I'll similarly assume silent > agreement to the discussed follow-up patches (dropping memory > barriers in a few places as well as converting __vmread() along the > lines of __vmread_safe()) once done, submitted, and reviewed. > > Jan > One thing I have noticed from subsequent reading of processor manuals is that reading from control registers are not actually serialising. It would be useful to get some comments about the in-processor optimisation for runs of pushes/pops, to determine whether it is a good idea interrupting the run. Having said that, the changes of any difference being measurable is slim. ~Andrew