Re: [PATCH 0/2] Get rid of ndo_xmit_flush
From: Jesper Dangaard Brouer <hidden>
Date: 2014-08-27 13:57:07
On Wed, 27 Aug 2014 06:23:58 -0700 Eric Dumazet [off-list ref] wrote:
I am afraid Jesper tests are not complete to truly have a picture of the extra costs, because he made sure no false sharing was possible (A single cpu does everything and keeps skb in its cache)
I fully agree. My tests a very artificial benchmarks only for the optimal case. I do worry a bit, if writing skb->xmit_more in a more cache cold scenarios could hurt us (as that cacheline seems to be read mostly), but this is not a problem right now because it will always be cache hot, as we always clear the entire SKB in alloc. -- Best regards, Jesper Dangaard Brouer MSc.CS, Sr. Network Kernel Developer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer