From owner-freebsd-emulation@FreeBSD.ORG Fri Nov 23 14:20:08 2012 Return-Path: Delivered-To: freebsd-emulation@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 97A71D1A for ; Fri, 23 Nov 2012 14:20:08 +0000 (UTC) (envelope-from decke@bluelife.at) Received: from mail-ob0-f182.google.com (mail-ob0-f182.google.com [209.85.214.182]) by mx1.freebsd.org (Postfix) with ESMTP id 497098FC14 for ; Fri, 23 Nov 2012 14:20:08 +0000 (UTC) Received: by mail-ob0-f182.google.com with SMTP id 16so11562159obc.13 for ; Fri, 23 Nov 2012 06:20:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bluelife.at; s=google; h=mime-version:sender:x-originating-ip:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=Hw9Q+0/FJ/jDix9oaBBv9aDfZ3fKAn/7W/VN0Ov2/mI=; b=PixO5AmeCJAQEzbEorKy9ko1li73X8Ao0fYyFrl1piGA43Vs1iwEjg7XI58SZCthhI bIXuB8ufGm4SOPIJqHciMKzk9a2DY7Gah3AFu/mkZserH20rg85TmGZYHY3Uh5dzaN3i a/TMFSsqL/wrYseQbLksjF/fKvQrJs9KfM1lw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:sender:x-originating-ip:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :x-gm-message-state; bh=Hw9Q+0/FJ/jDix9oaBBv9aDfZ3fKAn/7W/VN0Ov2/mI=; b=kVV8yK+W6ZVGVkRydXHHiI5zSGc4aZGWK0i3MIsXlRKnzEQ4+NJn1ff3vshZzHNTN1 bGO9O8QbM73KChqsDDSjSu45fsR97+9kz4SyxYzl9pnBoDai+f47imcuFS9hcijZW4Yi BYfFookFFz+7RXvm0s1q1pW0jIxG23y+lrF491/k+a/IKTpt0CvIv2qh1o79Yj8OcfGD cLImo42cuM0FVbSbRnnpD+heJCm41HFyxyemtOeRzZrEVOaAP0TmmLYF3BVJS1QW8ZAd b7b3B9svwDHOyQjoBxtrRwmm1zE/sSyQTm5+VuwnxFGyb3bBomIDwVzjtTx4c4h5bHdq q3tw== MIME-Version: 1.0 Received: by 10.182.64.101 with SMTP id n5mr3008836obs.11.1353680407573; Fri, 23 Nov 2012 06:20:07 -0800 (PST) Sender: decke@bluelife.at Received: by 10.76.8.199 with HTTP; Fri, 23 Nov 2012 06:20:07 -0800 (PST) X-Originating-IP: [80.123.233.199] In-Reply-To: References: Date: Fri, 23 Nov 2012 15:20:07 +0100 X-Google-Sender-Auth: mvdIz4vVEtOgpFJteUi-j6rfNSM Message-ID: Subject: Re: VirtualBox 4.2.4 on FreeBSD 9.1-PRERELEASE problem: VMs behave very different when pinned to different cores From: =?ISO-8859-1?Q?Bernhard_Fr=F6hlich?= To: Alex Chistyakov Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQl68zaC/anH79udeIG/J+sso/E4MN1xvq7Jz/lrQnawrTh12wUzrt6WbvpVlMBGaV3nFpIh Cc: "freebsd-emulation@freebsd.org" X-BeenThere: freebsd-emulation@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Development of Emulators of other operating systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Nov 2012 14:20:08 -0000 On Fri, Nov 23, 2012 at 2:15 PM, Alex Chistyakov wrote: > Hello, > > I am back with another problem. As I discovered previously setting a > CPU affinity explicitly helps to get decent performance on guests, but > the problem is that guest performance is very different on core #0 and > cores #5 or #7. Basically when I use 'cpuset -l 0 VBoxHeadless -s > "Name" -v on' to start the VM it is barely usable at all. The best > performance results are on cores #4 and #5 (I believe they are the > same physical core due to HT). #7 and #8 are twice as slow as #5, #0 > and #1 are the slowest and other cores lay in the middle. > If I disable a tickless kernel on the guest running on #4 or #5 it > becomes as slow as a guest running on #7 so I suspect this is a > timer-related issue. > I also discovered that there are quite a lot of system interrupts on > slow guests (%si is about 10-15) but Munin does not render them on its > CPU graphs for some reason. > All my VMs are on cores #4 and #5 right now but I want to utilize > other cores too. I am not sure what to do next, this looks like a > VirtualBox bug. What can be done to solve this? I do not want to sound ignorant but what do you expect? Each VBox VM consists of somewhere around 15 threads and some of them are the vCPUs. You bind them all to the same CPU so they will fight for CPU time on that single core and latency will get unpredictable as well as performance. And then you add more and more craziness by running it on cpu0 and a HT enabled CPU ... -- Bernhard Froehlich http://www.bluelife.at/