Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Dor Laor
On 11/23/2010 08:41 AM, Avi Kivity wrote: On 11/23/2010 01:00 AM, Anthony Liguori wrote: qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching them to respond to these signals, introduce monitor commands that stop and start individual vcpus. The purpose of these commands

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Anthony Liguori
On 11/23/2010 12:41 AM, Avi Kivity wrote: On 11/23/2010 01:00 AM, Anthony Liguori wrote: qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching them to respond to these signals, introduce monitor commands that stop and start individual vcpus. The purpose of these

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Anthony Liguori
On 11/23/2010 02:16 AM, Dor Laor wrote: On 11/23/2010 08:41 AM, Avi Kivity wrote: On 11/23/2010 01:00 AM, Anthony Liguori wrote: qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching them to respond to these signals, introduce monitor commands that stop and start

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Avi Kivity
On 11/23/2010 03:51 PM, Anthony Liguori wrote: On 11/23/2010 12:41 AM, Avi Kivity wrote: On 11/23/2010 01:00 AM, Anthony Liguori wrote: qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching them to respond to these signals, introduce monitor commands that stop and

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Anthony Liguori
On 11/23/2010 08:00 AM, Avi Kivity wrote: If we could catch SIGSTOP, then it would be easy to unblock it only while running in guest context. It would then stop on exit to userspace. Yeah, that's not a bad idea. Except we can't. Yeah, I s:SIGSTOP:SIGUSR1:g. Using monitor commands is

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-23 Thread Avi Kivity
On 11/23/2010 04:24 PM, Anthony Liguori wrote: Using monitor commands is fairly heavyweight for something as high frequency as this. What control period do you see people using? Maybe we should define USR1 for vcpu start/stop. What happens if one vcpu is stopped while another is

Re: [Qemu-devel] [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands

2010-11-22 Thread Avi Kivity
On 11/23/2010 01:00 AM, Anthony Liguori wrote: qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching them to respond to these signals, introduce monitor commands that stop and start individual vcpus. The purpose of these commands are to implement CPU hard limits using an