Re: [patch] voluntary-preempt-2.6.8.1-P1

[Ingo Molnar]

* Lee Revell <rlrevell@xxxxxxxxxxx> wrote:

> > > Anyway, the change to sched.c fixes the mlockall bug, it works
> > > perfectly now.  Thanks!
> > 
> > great! This fix also means that we've got one more lock-break in the
> > ext3 journalling code and one more lock-break in dcache.c. I've released
> > -P1 with the fix included:
> > 
> >  http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8.1-P1
> > 
> 
> The highest latency I am seeing now is the rhine_check_duplex problem. 
> Should I try making mdio_delay an NOOP?

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.)

	Ingo
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