Re: [accounting regression since rc1] scheduler updates

Ingo Molnar
2007-08-21T11:30:59Z

* Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> Am Dienstag, 21. August 2007 schrieb Ingo Molnar:
> > you mean to revert b27f03d4bd? I'd really like to see this fixed for
> > real for s390 + CONFIG_VIRT_CPU_ACCOUNTING=y. (which seems to be the
> > only case affected)
>
> Not a complete revert, but an ifdef-workaround. I wrote this patch last week
> and you were on cc:
> http://marc.info/?l=linux-mm-commits&m=118737949222362&w=2
>
> This patch should fix s390 and let everybody else use your new code.
> If you are conviced that we get a better solution before 2.6.23 hits
> the street, thats fine with me.

what do you think about the rq_clock() #ifdef i did in the previous mail
plus you making sched_clock() virtual? That way you can keep
scheduler_tick() driven by real-time, although that generally will cause
artifacts with SMP load-balancing too. (that was true in the past too)

but i dont mind your patch either - it's really the architecture's
choice how visible it wants to make external load to the task stats of
its virtual machines. I think it is more logical to say that 100% CPU
time displayed in 'top' means that the task got all the CPU time it
asked for from the virtual machine. (and if you are curious about how
much time was stolen from the virtual box altogether you look at the
stolen-time stats in isolation.)

Ingo