Subject: RE: Dual core Athlons and unsynced TSCs
From: Lee Revell <rlrevell@joe-job.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Roger Heflin <rheflin@atipa.com>,
       "'linux-kernel'" <linux-kernel@vger.kernel.org>
In-Reply-To: <Pine.LNX.4.58.0601131338370.6971@gandalf.stny.rr.com>
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	 <Pine.LNX.4.58.0601131338370.6971@gandalf.stny.rr.com>
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Date: Fri, 13 Jan 2006 13:55:05 -0500
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On Fri, 2006-01-13 at 13:41 -0500, Steven Rostedt wrote:
> On Fri, 13 Jan 2006, Lee Revell wrote:
> 
> > On Fri, 2006-01-13 at 12:52 -0500, Steven Rostedt wrote:
> > > On Fri, 13 Jan 2006, Lee Revell wrote:
> > >
> > > > I don't have hardware to test this, can you confirm that the only
> > > > workaround needed is to boot with "clock=pmtmr"?
> > >
> > > For which kernel?
> >
> > I believe the problem exists on all kernels, it should not matter.
> 
> 
> Well, I just booted up (and am currently running) 2.6.15-rt4-sr2 and I
> used "clock=pmtmr".  I haven't got any
> 
> read_tsc: ACK! TSC went backward! Unsynced TSCs?
> 
> 
> If that's what you want to know?

I want to know if clock_gettime(CLOCK_MONOTONIC, *ts) is actually
guaranteed to be monotonic on these machines AKA do we break POSIX
compliance or not.

Lee

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