Date: Mon, 13 Feb 2006 10:13:48 -0500 From: Marcos Bedinelli <bedinelli@madhaus.cns.utoronto.ca> To: dima <_pppp@mail.ru> Cc: freebsd-net@freebsd.org Subject: Re: Network performance in a dual CPU system Message-ID: <c43c3da43a681d7c2b43663bfeb397cc@madhaus.cns.utoronto.ca> In-Reply-To: <E1F7fzS-000GUW-00._pppp-mail-ru@f16.mail.ru> References: <E1F7fzS-000GUW-00._pppp-mail-ru@f16.mail.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi, On 10-Feb-06, at 16:39, dima wrote: > The second CPU wouldn't help you for sure. There's only one [swi1: > net] kernel thread which deals with all the kernel traffic. The option > of per-CPU [swi: net] threads was discussed on freebsd-arch@ several > months ago, but it wouldn't be implemented soon. > So, the only hardware option is installing the fastest CPU possible. Ok, the statement above answers my first question clearly and concisely (although I must confess I am a bit confused after reading Robert Watson's message). > There are several software (FreeBSD specific) options though: > 1. You should surely try polling(4). 50kpps mean 50000 interrupts and > the same amount of context switches, which are quite expensive. > 2. FastForwarding. It's the most suitable for you. As I know, Quagga > inserts its dynamic routes to the system routing table. And > FastForwarding is aware of routing table and firewall rules. And the > most exciting: you can switch it on/off without reboot: > # sysctl net.inet.ip.fastforwarding=1 This morning a tried suggestion number 2. I had HOST-A running a ping session to HOST-B. Between hosts A and B there was the heavily loaded FreeBSD machine in question. As soon as I entered 'sysctl net.inet.ip.fastforwarding=1' the ping session died. Switching fastforwarding back to 0 resumed the session. It's very unfortunate we can't afford to have that machine down, even for a couple of minutes, during daytime. I guess I'll have to read more about polling and the net.inet.ip.fastforwarding option, before giving it another try (probably around 3 a.m.) Thanks for your reply. Regards, -- Marcos
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?c43c3da43a681d7c2b43663bfeb397cc>