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Subject: Re: [RFC][PATCH] SCHED_EDF scheduling class
From: Raistlin <raistlin@linux.it>
To: roel kluin <roel.kluin@gmail.com>
Cc: Linus Walleij <linus.ml.walleij@gmail.com>,
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On Tue, 2009-09-29 at 20:15 +0200, roel kluin wrote:
> shouldn't the NULL test be moved upwards, to prevent a dereference of
> a NULL pointer?=20
I definitely think you _do_ are right, many thanks! :-P

> Also I notice that `timespec_to_ns(&param_ex->sched_period)'
> is called twice, maybe gcc does this but can't we do something like
>=20
>         if (edf_policy(policy)) {
>                 if (param_ex =3D=3D NULL || param_ex->sched_priority !=3D=
 0)
>                         return -EINVAL;
>                 s64 psp =3D timespec_to_ns(&param_ex->sched_period);
>                 if (psp =3D=3D 0 || psp < timespec_to_ns(&param_ex->sched=
_runtime))
>                         return -EINVAL;
>         }
>=20
Well, don't know... I guess the compiler do _something_ (also since
timespec_to_ns is 'static inline') but, to be sincere, I've not looked
at the assembly yet... But I may check it out, at least for x86, and
then consider this. :)

Thanks very much for your comments and suggestions,
Dario

--=20
<<This happens because I choose it to happen!>> (Raistlin Majere)
----------------------------------------------------------------------
Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa  (Italy)

http://blog.linux.it/raistlin / raistlin@ekiga.net /
dario.faggioli@jabber.org

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