On Tue, 19 Apr 2016 14:33:02 +0100 Edward Cree <ec...@solarflare.com> wrote:
> Earlier discussions on this list[1] suggested that having multiple packets > traverse the network stack together (rather than calling the stack for each > packet singly) could improve performance through better cache locality. > This patch series is an attempt to implement this by having drivers pass an > SKB list to the stack at the end of the NAPI poll. The stack then attempts > to keep the list together, only splitting it when either packets need to be > treated differently, or the next layer of the stack is not list-aware. > > The first two patches simply place received packets on a list during the > event processing loop on the sfc EF10 architecture, then call the normal > stack for each packet singly at the end of the NAPI poll. > The remaining patches extend the 'listified' processing as far as the IP > receive handler. > > Packet rate was tested with NetPerf UDP_STREAM, with 10 streams of 1-byte > packets, and the process and interrupt pinned to a single core on the RX > side. > The NIC was a 40G Solarflare 7x42Q; the CPU was a Xeon E3-1220V2 @ 3.10GHz. > Baseline: 5.07Mpps > after patch 2: 5.59Mpps (10.2% above baseline) > after patch 8: 6.44Mpps (25.6% above baseline) Quite impressive! Thank you Edward, for working on this. It is nice to see that doing this actually gives a nice performance boost, it was mostly a theory of mine in [1]. (p.s. I'm currently a bit busy at MM-summit, but try to follow the thread. I want to try out your patchset once I return home again...) -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat Author of http://www.iptv-analyzer.org LinkedIn: http://www.linkedin.com/in/brouer [1] http://thread.gmane.org/gmane.linux.network/395502
