Re: [PATCH] x86: Run checksumming in parallel accross multiple alu's

From: Eric Dumazet
Date: Tue Oct 15 2013 - 20:34:17 EST


On Tue, 2013-10-15 at 09:21 -0700, Joe Perches wrote:

> Ingo, Eric _showed_ that the prefetch is good here.
> How about looking at a little optimization to the minimal
> prefetch that gives that level of performance.

Wait a minute, my point was to remind that main cost is the
memory fetching.

Its nice to optimize cpu cycles if we are short of them,
but in the csum_partial() case, the bottleneck is the memory.

Also I was wondering on the implications of changing reads order,
as it might fool cpu predictions.

I do not particularly care about finding the right prefetch stride,
I think Intel guys know better than me.


--
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/