Date: Sun, 29 Jun 2008 19:06:29 +1000 From: Andrew Snow <andrew@modulus.org> To: Paul <paul@gtcomm.net> Cc: FreeBSD Net <freebsd-net@freebsd.org> Subject: Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp] Message-ID: <48675095.7020008@modulus.org> In-Reply-To: <4867420D.7090406@gtcomm.net> References: <4867420D.7090406@gtcomm.net>
next in thread | previous in thread | raw e-mail | index | archive | help
The "em" driver currently only has a single worker/queue so will only use one CPU to process packets. However I remember reading that multi-threaded version of the driver is being worked on and is "coming soon", but there is no known ETA yet. I see you mentioned that you played with the receive descriptors and set that to 4096, which is good if your chipset supports it. But I can't see that you mentioned playing around with hw.em.rx_int_delay or tx_int_delay - have you tried this? By default rx_int_delay is disabled but it has the capability to lower CPU consumption if you enable it and it works on your chipset. By my reckoning, if you are aiming for a million pps, thats microsecond per packet, so you can afford to increase the delay quite alot, try 50 or 100 or even more? - Andrew
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?48675095.7020008>