Subject: Re: [PATCH -mm] [RFC] I/OAT: Handle incoming udp through ioatdma

From: jamal <[email-masked]>
Date: Thu, 29 Nov 2007 18:43:35 -0500

On Thu, 2007-29-11 at 12:08 -0800, Nelson, Shannon wrote:
> [RFC] I/OAT: Handle incoming udp through ioatdma
> 
> From: Shannon Nelson <[email-masked]>
> 
> If the incoming udp packet is larger than sysctl_udp_dma_copybreak, try
> pushing it through the ioatdma asynchronous memcpy.  This is very much
> the
> same as the tcp copy offload.  This is an RFC because we know there are
> stability problems under high traffic.

What stability problems?

Is there some magic sysctl_udp_dma_copybreak threshold value where you
start seeing the benefit of IOAT-ing? Since you mentioned
"students"<evil grin here>, it would be interesting to see data where
udp starts benefitting.

cheers,
jamal