From: Ingo Molnar <mingo@elte.hu>
To: john cooper <john.cooper@timesys.com>
Cc: "Bill Huey (hui)" <bhuey@lnxw.com>,
Esben Nielsen <simlo@phys.au.dk>,
linux-kernel@vger.kernel.org
Subject: Re: Priority Inheritance Test (Real-Time Preemption)
Date: Tue, 23 Nov 2004 10:21:52 +0100 [thread overview]
Message-ID: <20041123092152.GA5061@elte.hu> (raw)
In-Reply-To: <41A2902A.5050308@timesys.com>
* john cooper <john.cooper@timesys.com> wrote:
> >>I'd hazard a guess the reason existing implementations do not do this
> >>type of dependency-chain closure is the complexity of a general
> >>approach. [...]
> >
> >
> >please take a look at the latest patch, it is i believe handling all the
> >cases correctly. It certainly appears to solve the cases uncovered by
> >pi_test.
>
> Yes I see where you are walking the dependency chain
> in pi_setprio(). But this is under the global spinlock
> 'pi_lock'.
>
> My earlier comment was of the difficulty to establish fine
> grained locking, [...]
the issues raised in the paper and in this thread were much more
fundamental than SMP-scalability. Considering the costs of a hard-RT
mutex approach itself i dont think SMP-scalability is a primary issue
right now.
> [...] However I'd offer there is more concurrency possible in this
> design.
yeah, most likely - but correctness comes first. SMP scalability is
something that can be done later.
Ingo
next prev parent reply other threads:[~2004-11-23 8:20 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-21 20:29 Priority Inheritance Test (Real-Time Preemption) Esben Nielsen
2004-11-22 0:27 ` Ingo Molnar
2004-11-23 13:34 ` Ingo Molnar
2004-11-23 15:47 ` Esben Nielsen
2004-11-23 23:03 ` Esben Nielsen
2004-11-24 3:42 ` Ingo Molnar
2004-11-24 7:51 ` Ingo Molnar
2004-11-24 8:07 ` Ingo Molnar
2004-11-24 8:33 ` Esben Nielsen
2004-11-24 9:55 ` Ingo Molnar
2004-11-24 10:18 ` Ingo Molnar
2004-11-25 15:46 ` Esben Nielsen
2004-11-25 16:58 ` Ingo Molnar
2004-11-25 16:08 ` Esben Nielsen
2004-11-25 17:14 ` Ingo Molnar
2004-11-25 22:08 ` Esben Nielsen
2004-11-26 1:08 ` Ingo Molnar
2004-11-26 0:34 ` Ingo Molnar
2004-11-26 0:37 ` Ingo Molnar
2004-11-26 8:52 ` Esben Nielsen
2004-11-26 16:26 ` Esben Nielsen
2004-11-26 20:41 ` Ingo Molnar
2004-11-26 21:05 ` Ingo Molnar
2004-11-27 23:05 ` Esben Nielsen
2004-11-28 8:42 ` Ingo Molnar
2004-11-28 15:55 ` Esben Nielsen
2004-11-29 9:59 ` Ingo Molnar
2004-11-29 15:07 ` Esben Nielsen
2004-11-29 15:56 ` Ingo Molnar
2004-11-29 15:57 ` Ingo Molnar
2004-11-29 16:50 ` Esben Nielsen
2004-11-30 8:49 ` Ingo Molnar
2004-11-22 9:23 ` Bill Huey
2004-11-22 12:37 ` Ingo Molnar
2004-11-22 21:25 ` Bill Huey
2004-11-22 14:16 ` john cooper
2004-11-22 15:24 ` Ingo Molnar
2004-11-23 1:19 ` john cooper
2004-11-23 8:13 ` Esben Nielsen
2004-11-23 9:21 ` Ingo Molnar [this message]
2004-11-22 21:30 ` Bill Huey
2004-11-23 1:34 ` john cooper
2004-11-22 16:12 ` Esben Nielsen
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