From owner-freebsd-net@FreeBSD.ORG Tue Apr 28 21:25:39 2009 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 7C47A106566B for ; Tue, 28 Apr 2009 21:25:39 +0000 (UTC) (envelope-from andrew@modulus.org) Received: from email.octopus.com.au (email.octopus.com.au [122.100.2.232]) by mx1.freebsd.org (Postfix) with ESMTP id 3AE958FC14 for ; Tue, 28 Apr 2009 21:25:38 +0000 (UTC) (envelope-from andrew@modulus.org) Received: by email.octopus.com.au (Postfix, from userid 1002) id DCC9417899; Wed, 29 Apr 2009 07:10:34 +1000 (EST) X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on email.octopus.com.au X-Spam-Level: X-Spam-Status: No, score=-1.4 required=10.0 tests=ALL_TRUSTED autolearn=failed version=3.2.3 Received: from [10.1.50.60] (ppp121-44-112-205.lns10.syd6.internode.on.net [121.44.112.205]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: admin@email.octopus.com.au) by email.octopus.com.au (Postfix) with ESMTP id 7372F17178; Wed, 29 Apr 2009 07:10:30 +1000 (EST) Message-ID: <49F7709F.1020409@modulus.org> Date: Wed, 29 Apr 2009 07:09:51 +1000 From: Andrew Snow User-Agent: Thunderbird 2.0.0.14 (X11/20080523) MIME-Version: 1.0 To: Luigi Rizzo References: <36906055-E1AE-486B-BA77-D260E0609BBB@netasq.com> <50451.74235.qm@web63901.mail.re1.yahoo.com> <20090428150739.GC8430@onelab2.iet.unipi.it> In-Reply-To: <20090428150739.GC8430@onelab2.iet.unipi.it> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD Net Subject: Re: Interrupts + Polling mode (similar to Linux's NAPI) 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, 28 Apr 2009 21:25:39 -0000 Luigi Rizzo wrote: > If i am not mistaken we don't have generic support for interrupt moderation > in the kernel but that's a specific NIC feature: it works if the > hardware supports it, and it doesn't otherwise. > > Of course it would be possible to modify polling to implement > generic interrupt mitigation even without hardware support, so > you get the best of the two worlds. It seems to me that you're wasting your time if you are trying to achieve a high throughput in FreeBSD without using an Intel Pro/1000 or 10gbe networking card. So I don't know if anyone would really miss out if generic polling support was completely removed from the kernel and all efforts were then placed into improving other parts of network flow in the kernel which need more help. - Andrew