* Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> 2016-06-08 15:22 GMT+08:00 Ingo Molnar <mingo@xxxxxxxxxx>:
> >
> > * Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> >
> >> From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
> >>
> >> This patch adds guest steal-time support to full dynticks CPU
> >> time accounting. After the following commit:
> >>
> >> ff9a9b4c4334 ("sched, time: Switch VIRT_CPU_ACCOUNTING_GEN to jiffy granularity")
> >>
> >> ... time sampling became jiffy based, even if it's still listened
> >> to ring boundaries, so steal_account_process_tick() is reused
> >> to account how many 'ticks' are stolen-time, after the last accumulation.
> >
> > So the 'ring boundary' part still doesn't parse (neither grammatically nor
> > logically) - please rephrase it because I have no idea what you want to say here.
>
> It is original from this slides.
> http://ertl.jp/~shinpei/conf/ospert13/slides/FredericWeisbecker.pdf,
> slide 28.
Yes, I now understand that this is meant as 'context tracking is active', but I
don't understand the way you use it in this changelog's context.
Btw., the grammatically correct way to add that phrase would have been:
... time sampling became jiffy based, even if it's still listening to ring
boundaries, so steal_account_process_tick() is reused to account how many
'ticks' are stolen-time, after the last accumulation.
But I still don't understand it, nor did Paolo understand it.
Nor is there any 0/3 boilerplace description that gives some context about what
these changes are about. Exactly what do you mean by 'add steal-time support' - we
clearly had that before. So is your patch lifting some limitation? Or was
steal-time accounting totally inactive with certain dynticks configurations? The
changelog does not tell us anything about that...
I'd like to quote from a mail of Andrew Morton:
"Please update the changelog to describe the current behavior.
Please also describe why you think that behavior should be changed.
ie: what's the reason for this patch."
Thanks,
Ingo
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