From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: 2.6.12 Performance problems Date: Wed, 24 Aug 2005 21:51:57 -0700 Message-ID: <430D4E6D.1090200@candelatech.com> References: <20050824172631.11829.qmail@web33309.mail.mud.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: Jesper Juhl , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: To: danial_thom@yahoo.com In-Reply-To: <20050824172631.11829.qmail@web33309.mail.mud.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Danial Thom wrote: > I think the concensus is that 2.6 has made trade > offs that lower raw throughput, which is what a > networking device needs. So as a router or > network appliance, 2.6 seems less suitable. A raw > bridging test on a 2.0Ghz operton system: > > FreeBSD 4.9: Drops no packets at 900K pps > Linux 2.4.24: Starts dropping packets at 350K pps > Linux 2.6.12: Starts dropping packets at 100K pps I ran some quick tests using kernel 2.6.11, 1ms tick (HZ=1000), SMP kernel. Hardware is P-IV 3.0Ghz + HT on a new SuperMicro motherboard with 64/133Mhz PCI-X bus. NIC is dual Intel pro/1000. Kernel is close to stock 2.6.11. I used brctl to create a bridge with the two GigE adapters in it and used pktgen to stream traffic through it (250kpps in one direction, 1kpps in the other.) I see a reasonable amount of drops at 250kpps (60 byte packets): about 60,000,000 packets received, 20,700 dropped. Interestingly, the system is about 60% idle according to top, and still dropping pkts, so it would seem that the system could be better utilized! Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com