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From: "Gregory Haskins" <ghaskins@novell.com>
To: "Steven Rostedt" <rostedt@goodmis.org>
Cc: <a.p.zijlstra@chello.nl>, <mingo@elte.hu>, <bill.huey@gmail.com>,
	<kevin@hilman.org>, <tglx@linutronix.de>, <cminyard@mvista.com>,
	<dsingleton@mvista.com>, <dwalker@mvista.com>,
	"Moiz Kohari" <MKohari@novell.com>,
	"Peter Morreale" <PMorreale@novell.com>,
	"Sven Dietrich" <SDietrich@novell.com>, <dsaxena@plexity.net>,
	<acme@redhat.com>, <ak@suse.de>, <gregkh@suse.de>,
	<npiggin@suse.de>, <pavel@ucw.cz>, <linux-kernel@vger.kernel.org>,
	<linux-rt-users@vger.kernel.org>
Subject: Re: [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing toincludelateral priority
Date: Mon, 03 Mar 2008 08:55:30 -0700	[thread overview]
Message-ID: <47CBD922.BA47.005A.0@novell.com> (raw)
In-Reply-To: <Pine.LNX.4.58.0803031051410.19405@gandalf.stny.rr.com>

>>> On Mon, Mar 3, 2008 at 10:55 AM, in message
<Pine.LNX.4.58.0803031051410.19405@gandalf.stny.rr.com>, Steven Rostedt
<rostedt@goodmis.org> wrote: 

> On Mon, 3 Mar 2008, Gregory Haskins wrote:
> 
>> >>> On Mon, Mar 3, 2008 at 10:13 AM, in message
>> >
>> > See the issue. The RT task on CPU0 may experience huge latencies.
>>
>> Agreed, but equal priority threads can always cause unbounded latencies by 
> definition.  I.e. we only guarantee to the highest thread.
> 
> It should not when they are bounded to two separate CPUs, and are the
> highest priority tasks on those CPUS.  That will be hard to explain, how a
> the highest prio tasks bounded to a single CPU had an unbounded latency.
> With the patches presented, this can happen.

Indeed.  I see your point.  I will make this change in the next revision.

Thanks for the review!
-Greg




  reply	other threads:[~2008-03-03 16:02 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-25 16:00 [(RT RFC) PATCH v2 0/9] adaptive real-time locks Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing to include lateral priority Gregory Haskins
2008-03-03 15:13   ` Steven Rostedt
2008-03-03 15:41     ` [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing to includelateral priority Gregory Haskins
2008-03-03 15:55       ` Steven Rostedt
2008-03-03 15:55         ` Gregory Haskins [this message]
2008-02-25 16:00 ` [(RT RFC) PATCH v2 2/9] sysctl for runtime-control of lateral mutex stealing Gregory Haskins
2008-02-25 21:53   ` Pavel Machek
2008-02-25 22:57     ` Sven-Thorsten Dietrich
2008-02-25 23:00       ` Pavel Machek
2008-02-25 23:40         ` Sven-Thorsten Dietrich
2008-02-26  1:15       ` Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 3/9] rearrange rt_spin_lock sleep Gregory Haskins
2008-02-25 21:54   ` Pavel Machek
2008-02-26  0:45     ` Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 4/9] optimize rt lock wakeup Gregory Haskins
2008-03-03 15:37   ` Steven Rostedt
2008-03-03 15:41     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 5/9] adaptive real-time lock support Gregory Haskins
2008-02-25 22:03   ` Pavel Machek
2008-02-26  0:48     ` Gregory Haskins
2008-02-26 15:03     ` Gregory Haskins
2008-02-26 18:06       ` Pavel Machek
2008-02-26 18:01         ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 6/9] add a loop counter based timeout mechanism Gregory Haskins
2008-02-25 22:06   ` Pavel Machek
2008-02-25 22:19     ` Greg KH
2008-02-25 22:21       ` Pavel Machek
2008-02-25 22:39     ` Sven-Thorsten Dietrich
2008-02-26 15:09     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 7/9] adaptive mutexes Gregory Haskins
2008-02-25 22:09   ` Pavel Machek
2008-02-26  0:52     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 8/9] adjust pi_lock usage in wakeup Gregory Haskins
2008-02-25 22:10   ` Pavel Machek
2008-02-25 16:01 ` [(RT RFC) PATCH v2 9/9] remove the extra call to try_to_take_lock Gregory Haskins

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