From owner-freebsd-net@FreeBSD.ORG Tue Jul 1 03:34:53 2008 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DEC35106566C for ; Tue, 1 Jul 2008 03:34:53 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: from an-out-0708.google.com (an-out-0708.google.com [209.85.132.247]) by mx1.freebsd.org (Postfix) with ESMTP id 8F82C8FC29 for ; Tue, 1 Jul 2008 03:34:53 +0000 (UTC) (envelope-from sepherosa@gmail.com) Received: by an-out-0708.google.com with SMTP id b33so388054ana.13 for ; Mon, 30 Jun 2008 20:34:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=F1hv5LS2zU0lUMOVJO+Ny44Wk9VfvAQaiIQ9f1r+aW8=; b=Pwi4f9BMjDBKdZSQerJvpsygE9/bbOvgFIcJYgENyoKCsrPPK0Jyc7ck5PKXlZSI/s IbFwV9IM2qgsG0iJxywH3r7sI10AfuvknfoQeqj0baqcKkCXjhO/1lYGKv6xlRcL4k6Q cfEs4rLQEYSpArlPX6z7qazmLSqmfjnRvHvV0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=kO1JsrSsB/n8O09hOgSqEpZ4dO78RTR8qPKQgXFrcd2BxmHbfYQ+MWe6z3jmrewPoD l9Oc57QnilYxqPOSIOQWLpma6N0qgReK9q/9W/sU5CVk87txhnMqJ2GNpk3cHycNUAkP CFLA0eeJMeLAprIna6hStG/WHrV/z7sImHodE= Received: by 10.100.154.9 with SMTP id b9mr5062681ane.78.1214883292462; Mon, 30 Jun 2008 20:34:52 -0700 (PDT) Received: by 10.100.107.6 with HTTP; Mon, 30 Jun 2008 20:34:52 -0700 (PDT) Message-ID: Date: Tue, 1 Jul 2008 11:34:52 +0800 From: "Sepherosa Ziehau" To: Paul In-Reply-To: <4869A099.5070206@gtcomm.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <4867420D.7090406@gtcomm.net> <200806301944.m5UJifJD081781@lava.sentex.ca> <20080701004346.GA3898@stlux503.dsto.defence.gov.au> <20080701010716.GF3898@stlux503.dsto.defence.gov.au> <486986D9.3000607@monkeybrains.net> <48699960.9070100@gtcomm.net> <4869A099.5070206@gtcomm.net> Cc: freebsd-net@freebsd.org, Ingo Flaschberger , "Wilkinson, Alex" , "Support \(Rudy\)" Subject: Re: Freebsd IP Forwarding performance (question, and some info) [7-stable, current, em, smp] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Jul 2008 03:34:53 -0000 On 7/1/08, Paul wrote: > I have been unable to even come close to livelocking the machine with the em > driver interrupt moderation. Yeah, system will not be livelocked. But even setting its imtimer to 4000, the overall system response is still worse than using polling @4000 with a 9402PT. > So that to me throws polling out the window. I tried 8000hz with polling I don't believe high polling rate will improve forwarding performance. I used to set polling rate to 2000hz, burst max to 750 and each burst to 60. > modified to allow 10000 burst and it makes no difference > in the amount of pps I can jam through.. It' seems to be limited by the > routing path in the kernel more than anything else. > > If a driver/hardware didn't support interrupt mitigation then it would > definitely lock the machine. So polling(4) still has its place. Best Regards, sephe -- Live Free or Die