From owner-freebsd-net@FreeBSD.ORG Wed Dec 11 04:11:41 2013 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 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 228EBD44; Wed, 11 Dec 2013 04:11:41 +0000 (UTC) Received: from mail-qa0-x22f.google.com (mail-qa0-x22f.google.com [IPv6:2607:f8b0:400d:c00::22f]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id A57AC10A9; Wed, 11 Dec 2013 04:11:40 +0000 (UTC) Received: by mail-qa0-f47.google.com with SMTP id w5so4406083qac.13 for ; Tue, 10 Dec 2013 20:11:39 -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=SLBr3LGofGn1KIxIctp3mP4zdDXVxsPKvdV6S2uTgpw=; b=fSmke5xLmducRAmpymgyIczduMtGs2RR5kjoLKKtSzck6RDbGymb2TtlcXOwjVoY9o DELOCW7OX6ApszgrM8ztK0+7IOJLWI5LEacIvK2MWZKZgV7pUeFYu2TVaZjW+w1K+P5P ICmeS85rsnVZaUakNNSQkRsITG/UPQIHWjdoVJYJM3Tnkjj8GYAH633vF3dofoO0D6rY QTnk/BU4jGqy56gid/N/JR+Jc/29OzZNRHV0TBAhjqvUNu+akitZRUjQzYzpXhg+D6Ap D6UfhuKBixqtP2YlALQBTFXrQl83fc2W87VLdKelWqCbcXVtEGnCg0WAOHJbJ7MrGSdb eKMQ== MIME-Version: 1.0 X-Received: by 10.224.80.129 with SMTP id t1mr162289103qak.95.1386735099825; Tue, 10 Dec 2013 20:11:39 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.224.53.200 with HTTP; Tue, 10 Dec 2013 20:11:39 -0800 (PST) In-Reply-To: References: <521B9C2A-EECC-4412-9F68-2235320EF324@lurchi.franken.de> <20131202022338.GA3500@michelle.cdnetworks.com> <20131203021658.GC2981@michelle.cdnetworks.com> <20131205223711.GB55638@funkthat.com> <3576B69E-E943-46E0-83E5-0B2194A44ED0@lurchi.franken.de> <20131206202012.GG55638@funkthat.com> <609C63CD-9332-4EAE-AACE-5B911416DF80@lurchi.franken.de> <9E163DC1-D647-4E19-BE23-44E5DFE2F284@lurchi.franken.de> Date: Tue, 10 Dec 2013 20:11:39 -0800 X-Google-Sender-Auth: yv6YQYNHAzOXo41ejA7vm30Tn_s Message-ID: Subject: Re: A small fix for if_em.c, if_igb.c, if_ixgbe.c From: Adrian Chadd To: Jack Vogel Content-Type: text/plain; charset=ISO-8859-1 Cc: Yong-Hyeon Pyun , John Baldwin , "freebsd-net@freebsd.org list" , John-Mark Gurney , Jack F Vogel , Michael Tuexen X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Dec 2013 04:11:41 -0000 Cool, no worries. -a On 10 December 2013 00:40, Jack Vogel wrote: > Hey Adrian, > > Didn't want you to think I was ignoring you, just kind of in the middle of > some deadline issues and was not able to give this a lot of cycles. > > I've been reading the email seeing if some kind of consensus was formed, > so far I'm not strongly convinced what's right. Does someone feel there is > an urgent need to get this changed? > > Cheers, > > Jack > > > > On Mon, Dec 9, 2013 at 11:37 AM, Adrian Chadd wrote: >> >> Jack / John - thoughts? >> >> >> -a >> >> On 8 December 2013 19:44, Adrian Chadd wrote: >> > .. I'm saying that we should have if_transmit( )return an error only >> > on the current packet, and 0 if it was queued. >> > >> > We don't have a mechanism to say that a queued packet actually made it >> > onto the wire. Whether we should is a different discussion. >> > >> > Ie, after thinking about this some more, I'd like to: >> > >> > * change if_transmit in these drivers to do exactly what you suggest - >> > it should return an error only if the given packet couldn't be queued. >> > It shouldn't matter whether it is later transmitted or not - we don't >> > have a feedback mechanism for that. >> > * figure out a very specific definition of what xxx_mq_start_locked() >> > should return - my gut feeling is an error if it couldn't queue a >> > frame, and 0 if it dispatched a frame to the hardware - and then make >> > the code match this definition. >> > >> > >> > >> > -adrian > >