Brandeburg, Jesse wrote:
On Mon, 5 Jun 2006, Rick Jones wrote:
Kok, Auke wrote:
It was brought to our attention that the prefetches break e1000 traffic
on xscale/arm architectures. Remove them for now. We'll let them
stay in mm for a while, or find a better solution to enable.
Out of curiousity, what breaks?
Hi Rick, according to our reporter, receives break. The prefetch (not
always, but sometimes) lets the processor get junk from the prefetched
area. Apparently this version of arm doesn't quite do as strict
enforcement of bus snoops as x86, ia64, (and even pSeries!) does.
Bear with me, I'm a software guy :) I interpret that to mean that the
processor is basically broken? If so, wouldn't it be the case that
prefetch() needs to become a noop on that processor?
This manifested with a large drop in receive peformance using TCP,
probably because it was retransmitting frequently.
I forget - what were the gains on the other CPUs?
rick
Jesse
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
