Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-20 Thread Glauber de Oliveira Costa
On Dec 19, 2007 1:41 PM, Avi Kivity <[EMAIL PROTECTED]> wrote: > Glauber de Oliveira Costa wrote: > > Changes in rate does not sound good. It's possibly what's screwing up > > my paravirt clock implementation in smp. > > > > You should renew the timebase on vcpu migration, and hook cpufreq so >

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-20 Thread Glauber de Oliveira Costa
On Dec 19, 2007 1:41 PM, Avi Kivity [EMAIL PROTECTED] wrote: Glauber de Oliveira Costa wrote: Changes in rate does not sound good. It's possibly what's screwing up my paravirt clock implementation in smp. You should renew the timebase on vcpu migration, and hook cpufreq so that changes

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Amit Shah
On Wednesday 19 December 2007 21:02:06 Glauber de Oliveira Costa wrote: > On Dec 19, 2007 12:27 PM, Avi Kivity <[EMAIL PROTECTED]> wrote: > > Ingo Molnar wrote: > > > * Avi Kivity <[EMAIL PROTECTED]> wrote: > > >> Avi Kivity wrote: > > >>> Testing shows wrmsr and rdtsc function normally. > > >>>

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Glauber de Oliveira Costa wrote: Changes in rate does not sound good. It's possibly what's screwing up my paravirt clock implementation in smp. You should renew the timebase on vcpu migration, and hook cpufreq so that changes in frequency are reflected in the timebase. Since the host

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Glauber de Oliveira Costa
On Dec 19, 2007 12:27 PM, Avi Kivity <[EMAIL PROTECTED]> wrote: > Ingo Molnar wrote: > > * Avi Kivity <[EMAIL PROTECTED]> wrote: > > > > > >> Avi Kivity wrote: > >> > >>> Testing shows wrmsr and rdtsc function normally. > >>> > >>> I'll try pinning the vcpus to cpus and see if that helps. > >>> >

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: try this test perhaps in an SMP guest: http://people.redhat.com/mingo/time-warp-test/time-warp-test.c you can ignore TSC warps - but no GTOD or CLOCK warps should occur. On a broken guest kernel, I see gtod and clock warps. On a good guest kernel, I do not,

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Ingo Molnar
try this test perhaps in an SMP guest: http://people.redhat.com/mingo/time-warp-test/time-warp-test.c you can ignore TSC warps - but no GTOD or CLOCK warps should occur. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: * Avi Kivity <[EMAIL PROTECTED]> wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the guest read the physical CPU's TSC? That would be trouble.

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: * Avi Kivity <[EMAIL PROTECTED]> wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the guest read the physical CPU's TSC? That would be trouble.

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Ingo Molnar
* Avi Kivity <[EMAIL PROTECTED]> wrote: > Avi Kivity wrote: >> Testing shows wrmsr and rdtsc function normally. >> >> I'll try pinning the vcpus to cpus and see if that helps. >> > > It does. do we let the guest read the physical CPU's TSC? That would be trouble. Ingo -- To

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Avi Kivity wrote: Ingo Molnar wrote: While the change mentions that it fixes a time warp bug, it also says it should be rare. So clearly kvm smp tsc handing is buggy. Ingo/Thomas, (or anybody else), do you have any insight as to what kvm can be doing wrong to trigger this behavior?

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Avi Kivity wrote: Ingo Molnar wrote: While the change mentions that it fixes a time warp bug, it also says it should be rare. So clearly kvm smp tsc handing is buggy. Ingo/Thomas, (or anybody else), do you have any insight as to what kvm can be doing wrong to trigger this behavior?

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Ingo Molnar
* Avi Kivity [EMAIL PROTECTED] wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the guest read the physical CPU's TSC? That would be trouble. Ingo -- To unsubscribe from this

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: * Avi Kivity [EMAIL PROTECTED] wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the guest read the physical CPU's TSC? That would be trouble.

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: * Avi Kivity [EMAIL PROTECTED] wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the guest read the physical CPU's TSC? That would be trouble.

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Ingo Molnar
try this test perhaps in an SMP guest: http://people.redhat.com/mingo/time-warp-test/time-warp-test.c you can ignore TSC warps - but no GTOD or CLOCK warps should occur. Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Ingo Molnar wrote: try this test perhaps in an SMP guest: http://people.redhat.com/mingo/time-warp-test/time-warp-test.c you can ignore TSC warps - but no GTOD or CLOCK warps should occur. On a broken guest kernel, I see gtod and clock warps. On a good guest kernel, I do not,

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Avi Kivity
Glauber de Oliveira Costa wrote: Changes in rate does not sound good. It's possibly what's screwing up my paravirt clock implementation in smp. You should renew the timebase on vcpu migration, and hook cpufreq so that changes in frequency are reflected in the timebase. Since the host

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Glauber de Oliveira Costa
On Dec 19, 2007 12:27 PM, Avi Kivity [EMAIL PROTECTED] wrote: Ingo Molnar wrote: * Avi Kivity [EMAIL PROTECTED] wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the vcpus to cpus and see if that helps. It does. do we let the

Re: [kvm-devel] Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-19 Thread Amit Shah
On Wednesday 19 December 2007 21:02:06 Glauber de Oliveira Costa wrote: On Dec 19, 2007 12:27 PM, Avi Kivity [EMAIL PROTECTED] wrote: Ingo Molnar wrote: * Avi Kivity [EMAIL PROTECTED] wrote: Avi Kivity wrote: Testing shows wrmsr and rdtsc function normally. I'll try pinning the

Re: Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Avi Kivity
Ingo Molnar wrote: While the change mentions that it fixes a time warp bug, it also says it should be rare. So clearly kvm smp tsc handing is buggy. Ingo/Thomas, (or anybody else), do you have any insight as to what kvm can be doing wrong to trigger this behavior? hm. Those time warps

Re: Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Ingo Molnar
* Avi Kivity <[EMAIL PROTECTED]> wrote: > Booting RHEL 5 i386 in kvm with -no-kvm-irqchip -smp 4 will hang in udev. > I bisected this to a change in the _guest_ kernel: > >> commit 95492e4646e5de8b43d9a7908d6177fb737b61f0 >> Author: Ingo Molnar <[EMAIL PROTECTED]> >> Date: Fri Feb 16

Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Avi Kivity
Booting RHEL 5 i386 in kvm with -no-kvm-irqchip -smp 4 will hang in udev. I bisected this to a change in the _guest_ kernel: commit 95492e4646e5de8b43d9a7908d6177fb737b61f0 Author: Ingo Molnar <[EMAIL PROTECTED]> Date: Fri Feb 16 01:27:34 2007 -0800 [PATCH] x86: rewrite SMP TSC sync

Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Avi Kivity
Booting RHEL 5 i386 in kvm with -no-kvm-irqchip -smp 4 will hang in udev. I bisected this to a change in the _guest_ kernel: commit 95492e4646e5de8b43d9a7908d6177fb737b61f0 Author: Ingo Molnar [EMAIL PROTECTED] Date: Fri Feb 16 01:27:34 2007 -0800 [PATCH] x86: rewrite SMP TSC sync code

Re: Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Ingo Molnar
* Avi Kivity [EMAIL PROTECTED] wrote: Booting RHEL 5 i386 in kvm with -no-kvm-irqchip -smp 4 will hang in udev. I bisected this to a change in the _guest_ kernel: commit 95492e4646e5de8b43d9a7908d6177fb737b61f0 Author: Ingo Molnar [EMAIL PROTECTED] Date: Fri Feb 16 01:27:34 2007 -0800

Re: Guest kernel hangs in smp kvm for older kernels prior to tsc sync cleanup

2007-12-18 Thread Avi Kivity
Ingo Molnar wrote: While the change mentions that it fixes a time warp bug, it also says it should be rare. So clearly kvm smp tsc handing is buggy. Ingo/Thomas, (or anybody else), do you have any insight as to what kvm can be doing wrong to trigger this behavior? hm. Those time warps