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Message-ID: <1331245665.25686.521.camel@gandalf.stny.rr.com>
Subject: Re: [ANNOUNCE] 3.2.9-rt17
From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>, LKML <linux-kernel@vger.kernel.org>,
        linux-rt-users <linux-rt-users@vger.kernel.org>
Date: Thu, 08 Mar 2012 17:27:45 -0500
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On Thu, 2012-03-08 at 23:20 +0100, Peter Zijlstra wrote:

> and with rt-mutex having the equal priority lock stealing this reverts
> to a plain test-and-set lock. There's only a tiny window in which A can
> actually get the lock and that is hampered by B's cpu owning the
> cacheline in exclusive mode.
> 
> I simply cannot see guaranteed progress here.

This can be easily fixed by not having the lateral steal when a lock has
a priority.

-- Steve