From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: paravirt clock stil causing hangs in kvm-65 Date: Sat, 19 Apr 2008 13:49:47 -0300 Message-ID: <20080419164947.GA31253@dmt> References: <20080407213457.GA4473@dmt> <20080419152947.GA30610@dmt> <5d6222a80804190922me58c7d1ycb5c38bcf13b94a8@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel@lists.sourceforge.net To: Glauber Costa , Gerd Hoffmann Return-path: Content-Disposition: inline In-Reply-To: <5d6222a80804190922me58c7d1ycb5c38bcf13b94a8@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org On Sat, Apr 19, 2008 at 01:22:28PM -0300, Glauber Costa wrote: > > I've been able to reproduce the problem. Symptoms are that when using > > NOHZ vcpu0 LAPIC timer is ticking far less than the others (apparently vcpu0 > > is the only one ticking "correctly"): > > > > > > nohz=on with kvmclock > > [root@localhost ~]# cat /proc/timer_stats | grep apic > > 13214, 8590 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 13214, 8589 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 13211, 8588 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 389, 8587 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > > > nohz=off > > 3253, 8672 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 2876, 8673 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 2543, 8674 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 2179, 8675 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > > > no-kvmclock > > 1017, 8808 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 1577, 8809 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 1708, 8807 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > 1812, 8806 qemu-system-x86 apic_mmio_write (apic_timer_fn) > > > > > > Glauber will start looking at this next week. > > > > > > > > >From what me and marcelo discussed, I think there's a possibility that > it has marginally something to do with precision of clock calculation. > Gerd's patches address that issues. Can somebody test this with those > patches (both guest and host), while I'm off ? Haven't seen Gerd's guest patches ? ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone