From owner-freebsd-net@FreeBSD.ORG Tue Mar 24 20:51:38 2015 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 8FC633D3; Tue, 24 Mar 2015 20:51:38 +0000 (UTC) Received: from mail-ie0-x22c.google.com (mail-ie0-x22c.google.com [IPv6:2607:f8b0:4001:c03::22c]) (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 54CE867B; Tue, 24 Mar 2015 20:51:38 +0000 (UTC) Received: by iedm5 with SMTP id m5so7657835ied.3; Tue, 24 Mar 2015 13:51:37 -0700 (PDT) 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=xKuprD5Z2ukDFs9CdlXm6TBOkRy3XYygOukxpyInV7o=; b=Id7Bo0R2ARLqnzxXxrUx7B+WSXK5mPwvi7rZ/XYwZRj8/AsrZGbStXICSD8flyd1Xw LR6Pnq1C/rjHAWz4/rRozajFn49L4nVydC55IWEx8weU2B3ruu540+p6F3xFK7FKJplN s9BquVKOgABnsEgNvCA8U2mNQ0U/GrWI7Hth+bAHvre2fbhSVgm6dqcoyvOPPs2RIUyW 2j/PV1TXAlZoaESnK5P0iN6+GUX5pcox5h5mFFFOYQWo5cObegz0dXbMkz/Loie0RvKy 3Y1DTiF9kYKFaeiAaSaysXRHj7Z1MIsOxQVn5+cNqXmc/wBZWu55RuocvJSsDuayqcpV QDuQ== MIME-Version: 1.0 X-Received: by 10.42.93.83 with SMTP id w19mr28220359icm.37.1427230297697; Tue, 24 Mar 2015 13:51:37 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.17.194 with HTTP; Tue, 24 Mar 2015 13:51:37 -0700 (PDT) In-Reply-To: <20150324154931.GC53237@strugglingcoder.info> References: <20150323233908.GT53237@strugglingcoder.info> <20150323234214.GU53237@strugglingcoder.info> <20150324154931.GC53237@strugglingcoder.info> Date: Tue, 24 Mar 2015 13:51:37 -0700 X-Google-Sender-Auth: -gFz-Z_5t4s_k8_4iBJn5v7eA-Y Message-ID: Subject: Re: Full 32bit flowid from igb(4) From: Adrian Chadd To: hiren panchasara Content-Type: text/plain; charset=UTF-8 Cc: Jack F Vogel , FreeBSD Net , erj@freebsd.org, Jack Vogel , Jason Wolfe 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: Tue, 24 Mar 2015 20:51:38 -0000 Hi, The main reason I didn't add it outside of RSS is that I didn't want to impact the behaviour that was there before. Before, it wasn't using the flowid - only the msix/queue id. I read the intel datasheets about that particular field - I'm pretty sure that by default we'll only see RSS hashed packets for IPv4/IPv6, however non v4/v6 packets won't have a flowid. There are also cases of the flow director or some hardware checksum config using the same field as the flowid. The /full/ solution would very carefully check the return status and ensure what's in the flowid field is a flowid. The "sometimes it may have a flowid, sometimes it won't" problem isn't so bad with kernel RSS enabled - it'll just software hash it. -adrian