Re: [PATCH v2 3/4] Documentation/scheduler/sched-deadline.txt: improve and clarify AC bits

[Ingo Molnar]

* Luca Abeni <luca.abeni@xxxxxxxx> wrote:

> Hi Ingo,
> 
> On Thu, 21 Aug 2014 15:38:37 +0200
> Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> [...]
> > > + If the total utilisation sum_i(WCET_i/P_i) (sum of the
> > > utilisations
> > > + WCET_i/P_i of all the tasks in the system - notice that when
> > > considering
> > > + multiple tasks, the parameters of the i-th one are indicated with
> > > the "_i"
> > > + suffix) is larger than M (with M equal to the number of CPUs),
> > > then the
> > > + system will surely not be able to respect all of the deadlines,
> > > and no
> > > + execution time is guaranteed for non real-time tasks, which risk
> > > to be
> > > + starved by real-time tasks.
> > 
> > The last part doesn't really parse as correct English for me - 
> > maybe also split this overly long sentence into two or three 
> > sentences, to make it easier to understand?
> Sorry about this; after re-reading the sentence, I agree it looks
> confusing. What about:

Looks good to me, with a few details:

> "
> If the total utilisation sum_i(WCET_i/P_i) is larger than M (with M
> equal to the number of CPUs), then the scheduler can not be able to
> respect all of the deadlines.

s/can not be able to respect/is unable to respect

> Note that the total utilisation is defined as the sum of the
> utilisations WCET_i/P_i of all the real-time tasks in the system (when
> considering multiple real-time tasks, the parameters of the i-th one are
> indicated with the "_i" suffix).

The parentheses are a bit confusing here - they come after a 
half finished sentence - which at the end turns out to have 
ended.

How about something like:

> Note that total utilisation is defined as the sum of the 
> utilisations WCET_i/P_i over all the real-time tasks in the 
> system. When considering multiple real-time tasks, the 
> parameters of the i-th task are indicated with the "_i" 
> suffix.

?

> Moreover, if the total utilisation is larger than M, then non real-time
> tasks risk to be starved by real-time tasks.

How about:

> Moreover, if the total utilisation is larger than M, then we 
> risk starving non- real-time tasks by real-time tasks.

?

Thanks,

	Ingo
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