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... > >>> > >>> > >> 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 affect meaurements. > >> > > > > This is what I did, I tested with -no-grapich in text console. > > Okay. Maybe cpu frequency scaling confused it then. Or something else?
I set it performance, frequency was locked at 2.1GHz. > >>> The guest is an idle kernel with HZ=1000. > >>> > >>> > >> Can you double check this? The dyntick results show that this is either > >> a 100Hz kernel, or that there is a serious bug in dynticks. > >> > > > > Ops I sent the wrong files, sorry. > > > > This is QEMU, with dynticks and HPET: > > > > % time seconds usecs/call calls errors syscall > > ------ ----------- ----------- --------- --------- ---------------- > > 52.10 0.002966 0 96840 clock_gettime > > 19.50 0.001110 0 37050 timer_gettime > > 10.66 0.000607 0 20086 timer_settime > > 10.40 0.000592 0 8985 2539 sigreturn > > 4.94 0.000281 0 8361 2485 select > > 2.41 0.000137 0 8362 gettimeofday > > ------ ----------- ----------- --------- --------- ---------------- > > 100.00 0.005693 179684 5024 total > > > > This looks like 250 Hz? Nope: # CONFIG_NO_HZ is not set # CONFIG_HZ_100 is not set # CONFIG_HZ_250 is not set # CONFIG_HZ_300 is not set CONFIG_HZ_1000=y CONFIG_HZ=1000 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? Luca
