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Date:   Sat, 10 Jun 2023 13:22:41 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Chen Yu <yu.c.chen@intel.com>
Cc:     mingo@kernel.org, vincent.guittot@linaro.org,
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Subject: Re: [PATCH 11/15] sched/eevdf: Better handle mixed slice length
Message-ID: <20230610112241.GB4253@hirez.programming.kicks-ass.net>
References: <20230531115839.089944915@infradead.org>
 <20230531124604.341527144@infradead.org>
 <ZIQZXMHvV3FKOquH@chenyu5-mobl2.ccr.corp.intel.com>
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On Sat, Jun 10, 2023 at 02:34:04PM +0800, Chen Yu wrote:

> > +static inline bool
> > +entity_has_slept(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
> > +{
> > +	u64 now;
> > +
> > +	if (!(flags & ENQUEUE_WAKEUP))
> > +		return false;
> > +
> > +	if (flags & ENQUEUE_MIGRATED)
> > +		return true;
> > +
> > +	now = rq_clock_task(rq_of(cfs_rq));
> > +	return (s64)(se->exec_start - now) >= se->slice;
> > +}
> A minor question, should it be now - se->exec_start ?
> (se->exec_start - now) is always negetive on local wakeup?

Yeah, also:

https://lkml.kernel.org/r/20230608124440.GB1002251@hirez.programming.kicks-ass.net

That is, it should be something along the lines of:

	delta = new - se->exec->start
	rerturn delta/W > vslice