From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Radensky Subject: Re: Ethernet bridge performance Date: Thu, 07 Aug 2003 20:19:11 +0300 Sender: netdev-bounce@oss.sgi.com Message-ID: <3F328A0F.3040005@allot.com> References: <3F3217E7.2080903@allot.com> <3F3284EA.5050406@candelatech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7BIT Cc: netdev@oss.sgi.com Return-path: To: Ben Greear Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Thanks for your help, Ben. What is skb-recycle patch and where can I find it ? Felix. Ben Greear wrote: > Felix Radensky wrote: > >> Hi, >> >> I'm evaluating a performance of a dual port ethernet bridge, and the >> results are a bit disappointing. I would appreciate any hints on >> improving >> the results. > > >> c01a13ac 7983 12.5065 eth_type_trans >> c01a1590 7629 11.9519 qdisc_restart >> c0197720 7365 11.5383 skb_release_data >> c010c170 5962 9.3403 do_gettimeofday > > > If that do_gettimeofday is happening in the skb rx code, then > you could gain ~10% by disabling it somehow..as it should not > matter for a bridge. I bet Robert's skb-recycle patch would > help here too, especially if you allowed the NICs to save up a large > number of skbs so that alloc was less likely to fail. > > Btw, I've considered saving, say, 10k skbs on a list in my module, > allocated by GFP_KERNEL at module load time, and using them when > GFP_ATOMIC skb_alloc fails in the IRQ handling portion of the code.... > > Anyone think that's a good idea? :) > > Ben >