From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:41295) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RvP3r-0002O7-9m for qemu-devel@nongnu.org; Thu, 09 Feb 2012 03:09:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RvP3l-0002Vl-8A for qemu-devel@nongnu.org; Thu, 09 Feb 2012 03:08:59 -0500 Received: from [222.73.24.84] (port=62474 helo=song.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RvP3k-0002R9-Ni for qemu-devel@nongnu.org; Thu, 09 Feb 2012 03:08:53 -0500 Date: Thu, 9 Feb 2012 16:08:33 +0800 From: Hu Tao Message-ID: <20120209080833.GD30616@localhost.localdomain> References: <1326731457-9056-1-git-send-email-pbonzini@redhat.com> <20120118073902.GA2265@localhost.localdomain> <4F183C7A.9070603@redhat.com> <20120130093318.GA4123@localhost.localdomain> <4F27E034.5060302@redhat.com> <20120209054607.GA30616@localhost.localdomain> <4F337230.4000506@redhat.com> MIME-Version: 1.0 In-Reply-To: <4F337230.4000506@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Subject: Re: [Qemu-devel] [PATCH v2 00/15] SCSI s/g + SCSI migration + virtio-scsi List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org On Thu, Feb 09, 2012 at 08:13:52AM +0100, Paolo Bonzini wrote: > On 02/09/2012 06:46 AM, Hu Tao wrote: > >>>> >I've re-tested today, with host kernel 2.6.35.6-45.fc14.x86_64, > >>>> >2.6.32-71.el6.x86_64, 3.1.0 and 3.3.0-rc1+, qemu version and guest > >>>> >configuration remain the same, including guest kernel. It apears > >>>> >that the problem appears only when the host kernel version is 3.1.0. > >Sorry, forget about the kernel versions. With very heavy IO load, it's > >easy to reproduce the problem. In my case, 300 disks were attached to a > >virtio-scsi HBA, and 300 dd processes were launched at the same time, > >each for a disk. > > Yes, we're not yet optimizing for _that_ kind of scalability. :) > That raw works is already surprising enough to me! Well, I'd like to say thanks for your works on virtio-scsi! > > What disk was it? Can you try on an SSD? A Hitachi HDS721010CLA332, SATA II, 7200rpm. I'm afraid I can't test on SSD since I have no SSD on hand.(and I don't think I'll have a SSD in the near future :| ) -- Thanks, Hu Tao