Re: [(RT RFC) PATCH v2 6/9] add a loop counter based timeoutmechanism

From: Sven-Thorsten Dietrich
Date: Mon Feb 25 2008 - 17:43:38 EST



On Mon, 2008-02-25 at 23:06 +0100, Pavel Machek wrote:
> On Mon 2008-02-25 11:01:08, Gregory Haskins wrote:
> > From: Sven Dietrich <sdietrich@xxxxxxxxxx>
>
> Why is this good idea?
>

The timeout is useful to eliminate excessive CPU utilization when
waiting for long-held critical sections.

The patch header should state this :) Will fix.

> > Signed-off-by: Sven Dietrich <sdietrich@xxxxxxxxxx>
> > ---
>
> >
> > +config RTLOCK_DELAY
> > + int "Default delay (in loops) for adaptive rtlocks"
> > + range 0 1000000000
> > + depends on ADAPTIVE_RTLOCK
> > + default "10000"
> > + help
> > + This allows you to specify the maximum attempts a task will spin
> > + attempting to acquire an rtlock before sleeping. The value is
> > + tunable at runtime via a sysctl. A setting of 0 (zero) disables
> > + the adaptive algorithm entirely.
> > +
>
> I believe you have _way_ too many config variables. If this can be set
> at runtime, does it need a config option, too?
>

Absolutely. The sysctl was added after-the-fact, so this is a relic, we
will remove the config option, and define the default timeout in the
appropriate header.

Sven

> Pavel

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