From: KY Srinivasan <k...@microsoft.com> Date: Tue, 3 Nov 2015 07:59:36 +0000
> I have implemented the scheme we had discussed a few weeks ago. In > this new implementation our driver is NOT requesting addition > headroom - rndis header and the per packet state is being maintained > outside of the skb. What I am seeing is that when I have > LL_MAX_HEADER set to 220 bytes, even though our driver is not using > the additional head room, I see about a 10% boost in the peak > performance (about 34 Gbps on a 40Gbps interface). However, when I > set the LL_MAX_HEADER value to the current default, the peak > performance drops back to what we currently have (around 31 > Gbps). In both these cases, there is no reallocation of skb since no > additional headroom is being requested and yet there is a > significant difference in performance. I trying to figure out why > this is the case, your insights will be greatly appreciated. It probably has something to do with cache line or data alignment. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
