From owner-freebsd-emulation@FreeBSD.ORG Fri Nov 23 13:15:18 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 1326627E for ; Fri, 23 Nov 2012 13:15:18 +0000 (UTC) (envelope-from alexclear@gmail.com) Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by mx1.freebsd.org (Postfix) with ESMTP id D88CC8FC14 for ; Fri, 23 Nov 2012 13:15:17 +0000 (UTC) Received: by mail-pa0-f54.google.com with SMTP id bi5so932450pad.13 for ; Fri, 23 Nov 2012 05:15:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=QFjloovj/Piy27FzEgomSxHZXfvAYEwg7tu0rqTAIRs=; b=Q1V+spHVUha4anCGAOFfTJfFesADhaqX7B1w3V637aiZNVQwOLNzssICZ9JYQM9qJh k4ePJa4ezCAgUXRA5M7pxfS2T4aOL2Igae+lJ1ZOLrT2Qyc1GMizNxXOwNaR3F/qjTCF BzF7uO0sfxI7as7xrBsGjnoIFLqon84+zpe6EX3JcU+KTefnMFOTygbsjBUJdJVlb0w1 0Mh47DLVKHticzQpGUjswObBwMYpEsYnxYLeSA8ofB9s49DT0SmHgTUVegcT4JKDG3Qy y9Uov3+f7DSPN9op7oC4Mi5T8bLndGSvWdYtdJ9GhGQayRRVpZ7fFUxxoDukQUPV6Ny5 hVkw== MIME-Version: 1.0 Received: by 10.66.79.167 with SMTP id k7mr10469427pax.24.1353676517475; Fri, 23 Nov 2012 05:15:17 -0800 (PST) Received: by 10.66.23.198 with HTTP; Fri, 23 Nov 2012 05:15:17 -0800 (PST) Date: Fri, 23 Nov 2012 16:15:17 +0300 Message-ID: Subject: VirtualBox 4.2.4 on FreeBSD 9.1-PRERELEASE problem: VMs behave very different when pinned to different cores From: Alex Chistyakov To: freebsd-emulation@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 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 13:15:18 -0000 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? Thank you! -- SY, Alex