[Cbe-oss-dev] [off topic] Debugging advice

[Gerhard Stenzel]

cbe-oss-dev-bounces+stenzel=de.ibm.com at ozlabs.org wrote on 07/30/2008
02:13:31 PM:

> On Wed, Jul 30, 2008 at 1:20 PM, Gerhard Stenzel
> <gerhard.stenzel at de.ibm.com> wrote:
> > cbe-oss-dev-bounces+stenzel=de.ibm.com at ozlabs.org wrote on 07/30/2008
> > 11:55:13 AM:
> >
> [snip]
> >
> > Is is possible that you are experiencing PPE side context switching of
your
> > kernel?
>
> I have thought of that, but I don't know how to verify it. I have
> looked a bit on the sizes of the DMA-transfers. The first DMA-transfer
> on the spe - which I guess is the SPE ELF-loader - has a size of 0xE80
> bytes while the DMA-transfer that I'm experiencing has a size of 0xB80
> bytes.
Run spu-top while running your program, maybe you see anything.
A context switch involves loading a small SPE program into the local store
which saves/restore part of the SPE state ... might be the wrong track
though.

Best regards,

Gerhard Stenzel, Linux on Cell Development, LTC
-----------------------------------------------------------------------------------------------------------------------------------

IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Martin Jetter | Geschäftsführung: Herbert
Kircher
Sitz der Gesellschaft: Böblingen | Registergericht: Amtsgericht Stuttgart,
HRB 243294