From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: performance trouble Date: Thu, 23 Feb 2012 10:38:07 +0200 Message-ID: <20120223083807.GA17505@redhat.com> References: <20120210100930.GW26955@nfs-rbx.ovh.net> <4F3A6260.7050208@redhat.com> <20120214134030.GD18866@redhat.com> <20120216085553.GX26955@nfs-rbx.ovh.net> <20120216090126.GC19771@redhat.com> <20120217085939.GZ26955@nfs-rbx.ovh.net> <20120217100714.GB29601@redhat.com> <20120217140107.GA26955@nfs-rbx.ovh.net> <20120219091315.GA10038@redhat.com> <20120222163356.GE26955@nfs-rbx.ovh.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , kvm@vger.kernel.org, Vadim Rozenfeld To: David Cure Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60979 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752268Ab2BWIiK (ORCPT ); Thu, 23 Feb 2012 03:38:10 -0500 Content-Disposition: inline In-Reply-To: <20120222163356.GE26955@nfs-rbx.ovh.net> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Feb 22, 2012 at 05:33:56PM +0100, David Cure wrote: > Le Sun, Feb 19, 2012 at 11:13:15AM +0200, Gleb Natapov ecrivait : > > > > > http://www.roullier.net/report-no-hpet.txt.gz > > > > > How have you acquired this trace? It does not trace all kvm events only > > those that have "set_irq" in them. > > I run : trace-cmd record -b 20000 -e kvm -P > Ah, I guess the reason is that it records events only of IO thread. You need to trace all vcpu threads too. Not sure trace-cmd allows more then one -P option though. > > Nothing particularly strange here. ~1745 IRQs are injected into the > > guest each second. RTC clock is configured to 1kH and other devices > > contribute ~721 irqs (MSI mostly) per second more. Hardly unusual. > > ok, so no ideas to decrease the response time ? > Without knowing the reason of the slowdown no. Probably you have the same problem as this other performance thread (frequent access to pm timer), but we need better trace to confirm that. -- Gleb.