From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: performance save/restore under xen-4.3.2 compared to kvm/qemu Date: Mon, 25 Aug 2014 13:38:38 +0100 Message-ID: <53FB2E4E.7000200@citrix.com> References: <53FB2AAD.8040705@citrix.com> <53FB49B7020000780002D36A@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53FB49B7020000780002D36A@mail.emea.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: ustermann.max@web.de, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 25/08/14 13:35, Jan Beulich wrote: >>>> On 25.08.14 at 14:23, wrote: >> I have also identified a bottleneck in the Linux PVOps kernel where the >> mmap batch ioctl takes a batch size of 1024 and generates 1024 batch >> hypercalls of batch size 1. Fixing this will certainly make the >> mapping/unmapping faster. > Didn't Mats Petersson post a patch for this quite a while ago? Did > this perhaps never get applied? > > Jan > That was a different issue if I remember correctly. I think it was to do with the classic kernel using ioremap() for foreign domain memory. ~Andrew