On 11/22/2010 05:56 PM, Chris Wright wrote:
* Anthony Liguori (aliguori@xxxxxxxxxxxxxxxxxx) wrote:
On 11/22/2010 05:04 PM, Chris Wright wrote:
* Anthony Liguori (aliguori@xxxxxxxxxx) 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.
In the past SIGSTOP has introduced time skew. Have you verified this
isn't an issue.
Time skew is a big topic. Are you talking about TSC drift,
pit/rtc/hpet drift, etc?
Sorry to be vague, but it's been long enough that I don't recall
the details. The guest kernel's clocksource effected how timekeeping
progressed across STOP/CONT (was probably missing qemu based timer ticks).
While this is not the same, made me wonder if you'd tested against that.
Yeah, it's definitely going to increase the likelihood of interrupt
coalescing but only as much as a contended CPU would already.
QEMU will keep getting timer ticks but the guest won't process them in a
timely fashion.
It's certainly going to stress periodic interrupt catch up code.
Heh, call it a feature for autotest ;)
Excellent idea :-)
Regards,
Anthony Liguori
thanks,
-chris
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