From owner-freebsd-net@FreeBSD.ORG Sat Mar 7 08:27:29 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 08A77891 for ; Sat, 7 Mar 2015 08:27:29 +0000 (UTC) Received: from mail-ie0-x22f.google.com (mail-ie0-x22f.google.com [IPv6:2607:f8b0:4001:c03::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BFD61DE5 for ; Sat, 7 Mar 2015 08:27:28 +0000 (UTC) Received: by iecrd18 with SMTP id rd18so608917iec.12 for ; Sat, 07 Mar 2015 00:27:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=zuK4GAiXb4uykjFQ+bt7+Jb2BMgOK7Glw4eas203B7o=; b=aQmeXWjHcV720lcTLHMjpmcQpkoudkc3BiH48mszNQ3DkuUGFEMcz+1pxeAe0IAZVO h8ZpHr/R3rhRoakNb6GhFCk6qmo9K/OW0FxvO5LnrnUXcP5mZJyCwYEahCoFm23Skogh oRzt3qgfzTJ7jo6P4RRheUcYYbaAkcxnewxRJA3XezMffGwVoDQLsyQWVbsCV6RZBpzD S4Oc63Y7RtBQ9BAEVyRgaXuSTyob9QQPmu75u4YXAK0cnGxbmEIzBDoworChnBrP/ADy PhgBgPZLRGvJ6CZ/tkgugBfFZNSaaQui9/+/mBhDNbFdyRhpLxVxT0qcv92h5pj4AVHE qPdQ== MIME-Version: 1.0 X-Received: by 10.42.101.8 with SMTP id c8mr14594389ico.61.1425716848250; Sat, 07 Mar 2015 00:27:28 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.36.17.66 with HTTP; Sat, 7 Mar 2015 00:27:28 -0800 (PST) In-Reply-To: References: Date: Sat, 7 Mar 2015 00:27:28 -0800 X-Google-Sender-Auth: 7N0A-ZtGmyJ3Sn0SZetEimjghzc Message-ID: Subject: Re: Network interrupt and NAPI in FreeBSD? From: Adrian Chadd To: Wei Hu Content-Type: text/plain; charset=UTF-8 Cc: "freebsd-net@freebsd.org" , Luigi Rizzo X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 07 Mar 2015 08:27:29 -0000 Hi, Well, hm. What's generating the interrupts? How many interrupts/second are you talking about here? People have asked about a NAPI style solution for FreeBSD for a while, but for most folk that are using one physical interface that does interrupt moderation/rate-limiting, it turns out to not be all that big a benefit. For boxes that haves multiple interfaces, or for VMs whose software interrupt path doesn't implement any kind of thresholds for interrupt moderation, it still can be a benefit. So maybe try looking at making your driver support POLLING and see what happens. Maybe virtualisation will be the straw that breaks the NAPI back for FreeBSD. ;) -a