From: Ingo Molnar <mingo@elte.hu>
To: Esben Nielsen <simlo@phys.au.dk>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Priority Inheritance Test (Real-Time Preemption)
Date: Fri, 26 Nov 2004 22:05:01 +0100 [thread overview]
Message-ID: <20041126210501.GA23381@elte.hu> (raw)
In-Reply-To: <20041126204138.GB21180@elte.hu>
* Ingo Molnar <mingo@elte.hu> wrote:
> it can produce such a flow on SMP, or if you add in a third non-RT
> task (task-C). Agreed?
here's the 4-task flow. I've simplified the operations to make it easier
to overview: "L1-success means" 'task locked lock1 and got it'.
"L1-wait" means it tried to get lock1 but has to wait. "RT-prio" means a
non-RT task got boosted to RT priority. "old-prio" means priority got
restored to the original non-RT value. "UL-1" means 'unlocked lock1'.
task-A task-B task-C task-RT
-------------------------------------------------------
L2-success
L1-success
L1-wait
. L2-wait
. boost-A
RT-prio . .
L1-wait . .
boost-B . .
. RT-prio . .
. [ 1 ms ] . .
. UL-1 . .
. !RT-prio . .
get-L1 . .
[ 1 ms ] . .
UL-1 . .
get-L1 .
UL-2 .
old-prio .
get-L2
L1-wait
boost-C
RT-prio .
[ 1 msec ] .
UL-1 .
old-prio .
get-L1
[ success ]
this is a 3 milliseconds worst-case. Ok?
Ingo
next prev parent reply other threads:[~2004-11-26 21:10 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 [this message]
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
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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