[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca Tettamanti
Il Wed, Aug 22, 2007 at 08:02:07AM +0300, Avi Kivity ha scritto: Luca Tettamanti wrote: Actually I'm having troubles with cyclesoak (probably it's calibration), numbers are not very stable across multiple runs... I've had good results with cyclesoak; maybe you need to run it in

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Avi Kivity
Luca Tettamanti wrote: Il Wed, Aug 22, 2007 at 08:02:07AM +0300, Avi Kivity ha scritto: Luca Tettamanti wrote: Actually I'm having troubles with cyclesoak (probably it's calibration), numbers are not very stable across multiple runs... I've had good results with

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca
On 8/22/07, Avi Kivity [EMAIL PROTECTED] wrote: Luca Tettamanti wrote: Il Wed, Aug 22, 2007 at 08:02:07AM +0300, Avi Kivity ha scritto: Luca Tettamanti wrote: Actually I'm having troubles with cyclesoak (probably it's calibration), numbers are not very stable across multiple runs...

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Avi Kivity
Luca wrote: This is QEMU, with dynticks and HPET: % time seconds usecs/call callserrors syscall -- --- --- - - 52.100.002966 0 96840 clock_gettime 19.500.001110 0 37050

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca
On 8/22/07, Avi Kivity [EMAIL PROTECTED] wrote: Luca wrote: This is QEMU, with dynticks and HPET: % time seconds usecs/call callserrors syscall -- --- --- - - 52.100.002966 0 96840

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca
On 8/22/07, Luca [EMAIL PROTECTED] wrote: I see a lot of sub ms timer_settime(). Many of them are the result of -expire_time being less than the current qemu_get_clock(). False alarm, this was a bug in the debug code :D Luca

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca
On 8/22/07, Luca [EMAIL PROTECTED] wrote: On 8/22/07, Avi Kivity [EMAIL PROTECTED] wrote: Luca wrote: This is QEMU, with dynticks and HPET: % time seconds usecs/call callserrors syscall -- --- --- - - 52.10

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Dan Kenigsberg
On Wed, Aug 22, 2007 at 06:38:18PM +0200, Luca wrote: and I'm reading it from /proc/config.gz on the guest. And a huge number of settime calls? Yes, maybe some QEMU timer is using an interval 1ms? Dan do you any any idea of what's going on? Not really...

[Qemu-devel] RE: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Dor Laor
This is QEMU, with dynticks and HPET: % time seconds usecs/call callserrors syscall -- --- --- - - - --- 52.100.002966 0 96840 clock_gettime 19.500.001110 0 37050 timer_gettime

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-22 Thread Luca
On 8/22/07, Dor Laor [EMAIL PROTECTED] wrote: This is QEMU, with dynticks and HPET: % time seconds usecs/call callserrors syscall -- --- --- - - - --- 52.100.002966 0 96840 clock_gettime

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-21 Thread Avi Kivity
Luca Tettamanti wrote: Run a 100Hz guest, measure cpu usage using something accurate like cyclesoak, with and without dynticks, with and without kvm. Ok, here I've measured the CPU usage on the host when running an idle guest. At 100Hz QEMU hpet4.8% dynticks

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-21 Thread Luca Tettamanti
Avi Kivity ha scritto: Luca Tettamanti wrote: At 1000Hz: QEMU hpet5.5% dynticks 11.7% KVM hpet3.4% dynticks7.3% No surprises here, you can see the additional 1k syscalls per second. This is very surprising to me. The 6.2% difference for the

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-21 Thread malc
On Tue, 21 Aug 2007, Luca Tettamanti wrote: Avi Kivity ha scritto: Luca Tettamanti wrote: At 1000Hz: QEMU hpet5.5% dynticks 11.7% KVM hpet3.4% dynticks7.3% No surprises here, you can see the additional 1k syscalls per second. This is very surprising

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-21 Thread Avi Kivity
Luca Tettamanti wrote: Actually I'm having troubles with cyclesoak (probably it's calibration), numbers are not very stable across multiple runs... I've had good results with cyclesoak; maybe you need to run it in runlevel 3 so the load generated by moving the mouse or breathing doesn't

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-20 Thread Luca Tettamanti
Il Sun, Aug 19, 2007 at 10:31:26PM +0300, Avi Kivity ha scritto: Luca wrote: On 8/19/07, Luca Tettamanti [EMAIL PROTECTED] wrote: +static uint64_t qemu_next_deadline(void) { +uint64_t nearest_delta_us = ULLONG_MAX; +uint64_t vmdelta_us; Hum, I introduced a bug

Re: [Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-20 Thread malc
On Mon, 20 Aug 2007, Luca Tettamanti wrote: Il Sun, Aug 19, 2007 at 10:31:26PM +0300, Avi Kivity ha scritto: Luca wrote: On 8/19/07, Luca Tettamanti [EMAIL PROTECTED] wrote: +static uint64_t qemu_next_deadline(void) { +uint64_t nearest_delta_us = ULLONG_MAX; +uint64_t vmdelta_us;

[Qemu-devel] RE: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure -take2

2007-08-19 Thread Dor Laor
I think this is a really nice and important patch set. Just a couple things: On Sun, 2007-08-19 at 00:02 +0200, Luca Tettamanti wrote: In this case the dyn-tick minimum res will be 1msec. I believe it should work ok since this is the case without any dyn-tick. Actually minimum resolution

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-19 Thread Luca
On 8/19/07, Luca Tettamanti [EMAIL PROTECTED] wrote: +static uint64_t qemu_next_deadline(void) { +uint64_t nearest_delta_us = ULLONG_MAX; +uint64_t vmdelta_us; Hum, I introduced a bug here... those vars should be signed. On the overhead introduced: how do you measure it? Luca

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-19 Thread Avi Kivity
Luca wrote: On 8/19/07, Luca Tettamanti [EMAIL PROTECTED] wrote: +static uint64_t qemu_next_deadline(void) { +uint64_t nearest_delta_us = ULLONG_MAX; +uint64_t vmdelta_us; Hum, I introduced a bug here... those vars should be signed. On the overhead introduced: how do you

[Qemu-devel] Re: [kvm-devel] [PATCH 0/4] Rework alarm timer infrastrucure - take2

2007-08-18 Thread Anthony Liguori
I think this is a really nice and important patch set. Just a couple things: On Sun, 2007-08-19 at 00:02 +0200, Luca Tettamanti wrote: In this case the dyn-tick minimum res will be 1msec. I believe it should work ok since this is the case without any dyn-tick. Actually minimum resolution