Re: [discuss] Re: [PATCH] Allow all Opteron processors to change pstate at same time

From: Pavel Machek
Date: Sat Jul 15 2006 - 21:55:04 EST


> On Thu, 2006-07-13 at 13:06 +0000, Pavel Machek wrote:
> > Can you run two such tests *in parallel*? That seemed to break it
> > really quickly.
> parallel sounds fun, but I don't get it. Two machine or trying to go
> online and offline at the same time? Firestorming two busy parallel

Trying to online and offline at the same time.

> while loops, one turning the core offline and the other online, did not
> bring an oops so I guess this kernel is in the clear in that regard.

Better run two tight loops, each doing online; offline. I got reports
it crashed machines before, but maybe it is solved.

> I can't get it to crash again and I am afraid that it crashed under an
> old devel kernel. After another ~20 hour test with heavy freq changes
> with the tscsync patch
>
> CPU 1: Syncing TSC to CPU 0.
> CPU 1: synchronized TSC with CPU 0 (last diff 4 cycles, maxerr 499
> cycles)
> ...
> CPU 2: Syncing TSC to CPU 0.
> CPU 2: synchronized TSC with CPU 0 (last diff -105 cycles, maxerr 600
> cycles)
> ...
> CPU 3: Syncing TSC to CPU 0.
> CPU 3: synchronized TSC with CPU 0 (last diff -122 cycles, maxerr 1126
> cycles)
>
>
> after 5 hours of no PowerNow!
>
> CPU 1: Syncing TSC to CPU 0.
> CPU 1: synchronized TSC with CPU 0 (last diff -3 cycles, maxerr 598
> cycles)
> ...
> CPU 2: Syncing TSC to CPU 0.
> CPU 2: synchronized TSC with CPU 0 (last diff -124 cycles, maxerr 1129
> cycles)
> ...
> CPU 3: Syncing TSC to CPU 0.
> CPU 3: synchronized TSC with CPU 0 (last diff -124 cycles, maxerr 1127
> cycles)
>
>
> huh?? I don't understand but it does not matter what I do or how long I
> do it, the difference looks to always be about the same.
>
> -joachim
>
>
>

--
Thanks, Sharp!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/