From: Peter Zijlstra <peterz@infradead.org>
To: Primiano Tucci <p.tucci@gmail.com>
Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org,
tglx <tglx@linutronix.de>
Subject: Re: Considerations on sched APIs under RT patch
Date: Wed, 21 Apr 2010 21:57:13 +0200 [thread overview]
Message-ID: <1271879833.1776.186.camel@laptop> (raw)
In-Reply-To: <x2mc5b2c05b1004211224s7825933dh531f2ed030610e9e@mail.gmail.com>
On Wed, 2010-04-21 at 21:24 +0200, Primiano Tucci wrote:
> Is it sure that calling a scheduler api won't induce a re-scheduling
> of the caller process (e.g. as in the case of a lock held by another
> processor)? It would be very unpleasant if the scheduling apis can
> induce re-scheduling, making the realization of a Real Time scheduling
> infrastructure completely un-deterministic.
No, any syscall can end up blocking/scheduling there are no exceptions.
But blocking doesn't mean its non-deterministic, esp. when coupled with
things like PI.
But you do have to treat system resources as such, that is they can (and
will) create cross-cpu dependencies, if you do not take that into
account you will of course be surprised.
next prev parent reply other threads:[~2010-04-21 19:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-19 20:48 Considerations on sched APIs under RT patch Primiano Tucci
2010-04-20 9:20 ` Peter Zijlstra
2010-04-20 21:56 ` Primiano Tucci
2010-04-20 23:00 ` Steven Rostedt
2010-04-21 5:16 ` Primiano Tucci
2010-04-21 8:49 ` Peter Zijlstra
2010-04-21 12:46 ` Steven Rostedt
2010-04-21 19:24 ` Primiano Tucci
2010-04-21 19:57 ` Peter Zijlstra [this message]
2010-04-21 20:38 ` Primiano Tucci
2010-04-21 20:58 ` Peter Zijlstra
2010-04-22 13:20 ` Steven Rostedt
2010-04-22 13:50 ` Primiano Tucci
2010-04-22 13:57 ` Peter Zijlstra
2010-04-22 15:40 ` Primiano Tucci
2010-04-22 16:28 ` Peter Zijlstra
2010-04-22 17:48 ` Bjoern Brandenburg
2010-04-22 19:33 ` Primiano Tucci
2010-04-21 12:56 ` Peter Zijlstra
2010-04-27 13:18 ` Thomas Gleixner
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