From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2 6/8] kvm tools: Add rwlock wrapper Date: Mon, 30 May 2011 15:44:09 +0300 Message-ID: <4DE39119.6050302@redhat.com> References: <1306748796.14564.62.camel@lappy> <20110530095451.GB8461@elte.hu> <20110530201110.f3bf20b5.yoshikawa.takuya@oss.ntt.co.jp> <1306753954.14564.92.camel@lappy> <20110530202646.eff0ea28.yoshikawa.takuya@oss.ntt.co.jp> <4DE381DB.8040804@redhat.com> <20110530114949.GD22324@elte.hu> <4DE387DA.3020307@redhat.com> <20110530123602.GK22324@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Takuya Yoshikawa , Sasha Levin , Pekka Enberg , kvm@vger.kernel.org, asias.hejun@gmail.com, gorcunov@gmail.com, prasadjoshi124@gmail.com, "Paul E. McKenney" , takuya.yoshikawa@gmail.com To: Ingo Molnar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51075 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752258Ab1E3Mof (ORCPT ); Mon, 30 May 2011 08:44:35 -0400 In-Reply-To: <20110530123602.GK22324@elte.hu> Sender: kvm-owner@vger.kernel.org List-ID: On 05/30/2011 03:36 PM, Ingo Molnar wrote: > You are probably right about 1024 CPUs. > > Right now i can produce something similar to it: 42 vcpus on a single > CPU: > > $ taskse 1 kvm run --cpus 42 > > And that hangs early on during bootup, around: > > [ 0.236000] Disabled fast string operations > [ 0.242000] #4 > [ 0.270000] Disabled fast string operations > [ 0.275000] #5 > [ 0.317000] Disabled fast string operations > [ 0.322000] #6 > [ 0.352000] Disabled fast string operations > [ 0.358000] #7 > [ 0.414000] Disabled fast string operations > > The threads seem to be livelocked: > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 22227 mingo 20 0 471g 95m 904 R 12.9 0.8 0:06.39 kvm > 22230 mingo 20 0 471g 95m 904 R 12.9 0.8 0:06.36 kvm > 22226 mingo 20 0 471g 95m 904 R 11.9 0.8 0:07.04 kvm > 22228 mingo 20 0 471g 95m 904 R 11.9 0.8 0:06.38 kvm > 22229 mingo 20 0 471g 95m 904 R 11.9 0.8 0:06.37 kvm > 22231 mingo 20 0 471g 95m 904 R 11.9 0.8 0:06.37 kvm > 22232 mingo 20 0 471g 95m 904 R 11.9 0.8 0:06.36 kvm > 22233 mingo 20 0 471g 95m 904 R 11.9 0.8 0:06.33 kvm > 7 root -2 19 0 0 0 S 2.0 0.0 1:12.53 rcuc0 > > with no apparent progress being made. > Well, strangely, 42-on-1 booted for me in qemu, and only got ridiculously slow in initrd. Three minutes and it's still booting. I don't really see how tools/kvm could cause this slowness, though. -- error compiling committee.c: too many arguments to function