Re: [PATCH] time,virt: resync steal time when guest & host lose sync

Wanpeng Li
2016-08-15T08:53:55Z

2016-08-12 23:58 GMT+08:00 Rik van Riel <riel@redhat.com>:
[...]
> Wanpeng, does the patch below work for you?

It will break steal time for full dynticks guest, and there is a
calltrace of thread_group_cputime_adjusted call stack, RIP is
cputime_adjust+0xff/0x130.

>
> Everybody else, does this patch look acceptable?
>
> ---8<---
> Subject: time,virt: do not limit steal_account_process_time
>
> When a guest is interrupted for a longer amount of time, missed clock
> ticks are not redelivered later. Because of that, we should not limit

Interesting, so do we need to add a feature like lapic timer
interrrupt coalescing in kvm? There is a RTC interrupt coalescing in
qemu to handle the scenario you mentioned for windows guest, if we
need a similar feature for linux guest? Paolo, Radim? I can try it if
you think it's valuable. :)

Regards,
Wanpeng Li