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Subject: Re: Increasing HZ (patch for HZ > 1000)
From: john stultz <johnstul@us.ibm.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: Jean-Marc Valin <Jean-Marc.Valin@USherbrooke.ca>,
       "Martin J. Bligh" <mbligh@aracnet.com>,
       Linux Kernel <linux-kernel@vger.kernel.org>
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On Fri, 2003-12-12 at 15:40, Pavel Machek wrote:
> > For now, my patch only allows up to around 10 kHz. At that frequency, I
> > don't hear anything because the noise is not loud enough (ear is much
> > more sensitive at 1 kHz). Also, I have around 10% overhead on my
> > Pentium-M 1.6 GHz, so I guess it's not for everyone. Extrapolating from
> > there, I'd also say that at 100 kHz, it wouldn't do anything but handle
> > the interrupts, which is slightly annoying when you want to actually get
> > some work done :)
> 
> I wonder what happens at 200kHz then; system might detect some lost
> ticks and keep running at very slow speed...

Indeed, with all the trouble HZ==1000 has caused, I'm thinking that
playing w/ HZ at 10k and 10 would be good stress tests for the time
subsystem.

I'd be interested in hearing how much drift people see when running w/
this patch. 

thanks
-john