Re: [Xen-devel] SEDF Scheduler slice time fix

[Atsushi SAKAI <sakaia@xxxxxxxxxxxxxx>]

Hello, Keir.

Thank you for you comments, and Sorry for disturbing you.
After your comments, I read the code again I found my mistake.

The real code is 
            ret.time = MIN(now + runinf->slice - runinf->cputime,
                           PERIOD_BEGIN(waitinf)) - now;

But I mis-reading the code of ')' position like this.
(This is not real code! in sched_sedf.c, I imagined code)

            ret.time = MIN(runinf->slice - runinf->cputime,
                           PERIOD_BEGIN(waitinf) - now);
                                                ^     ^


I must check carefully the code.


Atsushi SAKAI



>
>On 19 May 2006, at 03:46, Atsushi SAKAI wrote:
>
>>  Without this patch, CPU slice time is over allocated.
>>  (Because CPU slice time is absolute time at this moment(large value),
>>  but waitq time is relative time(small value),
>>  and MIN() selects smaller value(waitq).)
>
>A question then: you change the parameter to MIN() to no longer have 
>'now' added to it. Because both values are supposed to be relative not 
>absolute. If that's the case, should we be subtracting 'now' from the 
>result of MIN()? We currently do, and your patch does not change that. 
>So it seems a bit odd to me.
>
>  -- Keir
>
>
>

Atsushi SAKAI


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