time accounting problem (powerpc only?)

[Johannes Berg]

On Tue, 2007-11-27 at 20:57 +1100, Paul Mackerras wrote:
> Johannes Berg writes:
> 
> > Contrary to what I claimed later in the thread, my 64-bit powerpc box
> > (quad-core G5) doesn't suffer from this problem.
> > 
> > Does anybody have any idea? I don't even know how to debug it further.
> 
> I see it on my G4 powerbook.  However, a compute-bound task runs just
> as fast (i.e. completes in the same elapsed time) as on older kernels,
> so it does look like it is just an accounting problem.  If the CPU was
> really spending more than half its time servicing hardware interrupts,
> the task should take more than twice as long to complete.

Exactly. So where do I look for the accounting bug?

johannes
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 828 bytes
Desc: This is a digitally signed message part
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20071127/afb3f04c/attachment.pgp>