From owner-freebsd-net@freebsd.org Tue Sep 1 22:20:31 2015 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 071D69C8E5C for ; Tue, 1 Sep 2015 22:20:31 +0000 (UTC) (envelope-from rpaulo@me.com) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id E0CE7C54 for ; Tue, 1 Sep 2015 22:20:30 +0000 (UTC) (envelope-from rpaulo@me.com) Received: by mailman.ysv.freebsd.org (Postfix) id DFDB99C8E5A; Tue, 1 Sep 2015 22:20:30 +0000 (UTC) Delivered-To: net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DF7E49C8E59 for ; Tue, 1 Sep 2015 22:20:30 +0000 (UTC) (envelope-from rpaulo@me.com) Received: from mr11p00im-asmtp001.me.com (mr11p00im-asmtp001.me.com [17.110.69.252]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id B87CEC52; Tue, 1 Sep 2015 22:20:30 +0000 (UTC) (envelope-from rpaulo@me.com) Received: from akita.local (c-73-162-13-215.hsd1.ca.comcast.net [73.162.13.215]) by mr11p00im-asmtp001.me.com (Oracle Communications Messaging Server 7.0.5.35.0 64bit (built Mar 31 2015)) with ESMTPSA id <0NU0005RARDX0N20@mr11p00im-asmtp001.me.com>; Tue, 01 Sep 2015 22:20:23 +0000 (GMT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-09-01_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 suspectscore=2 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1412110000 definitions=main-1509010332 Message-id: <1441146021.1183.8.camel@me.com> Subject: Re: mbufq-less iwn(4) From: Rui Paulo To: Adrian Chadd , Gleb Smirnoff Cc: Lawrence Stewart , Andriy Voskoboinyk , "net@freebsd.org" Date: Tue, 01 Sep 2015 15:20:21 -0700 In-reply-to: References: <20150901112043.GB1023@glebius.int.ru> Content-type: text/plain; charset=UTF-8 X-Mailer: Evolution 3.16.4 FreeBSD GNOME Team Port MIME-version: 1.0 Content-transfer-encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.20 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 Sep 2015 22:20:31 -0000 On Tue, 2015-09-01 at 12:33 -0700, Adrian Chadd wrote: > hi, > > We have to do mbuf queues in drivers for wifi, because of 11n > aggregation. So on one hand we want to have if_transmit() apply > backpressure through the stack, but there's also going to be some > buffering. :P net80211 also has an ageq which was added to hold mbufs while the mesh peer link was being established. -- Rui Paulo