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Subject: Re: [patch] voluntary-preempt-2.6.8.1-P1
From: Lee Revell <rlrevell@joe-job.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Florian Schmidt <mista.tapas@gmx.net>,
       linux-kernel <linux-kernel@vger.kernel.org>,
       Felipe Alfaro Solana <felipe_alfaro@linuxmail.org>
In-Reply-To: <20040816043302.GA14979@elte.hu>
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On Mon, 2004-08-16 at 00:33, Ingo Molnar wrote:
> there's no mdio_delay() in via-rhine.c AFAICS. Could you add a pair of
> touch-latency calls to around this code in mdio_read():
> 
> +       touch_preempt_timing();
>         /* Wait for a previous command to complete. */
>         while ((readb(ioaddr + MIICmd) & 0x60) && --boguscnt > 0)
> +       touch_preempt_timing();
> 
> i suspect it's this one that introduces the biggest delay. Also:
> 
> +	touch_preempt_timing();
>         while ((readb(ioaddr + MIICmd) & 0x40) && --boguscnt > 0)
>                 ;
> +	touch_preempt_timing();
> 
> assuming that the latencies still show up even if delimited like this. 
> (note that this only changes the way the latency is tracked - the
> latency itself is still there so this isnt a fix.)
> 

Sure, but, what would this accomplish, if the latency is still there? 
Are we just trying to track down exactly where in the network driver
this is triggered?

Lee