From owner-freebsd-net@freebsd.org Thu Sep 3 21:42:46 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 EE92B9C9E64 for ; Thu, 3 Sep 2015 21:42:45 +0000 (UTC) (envelope-from adrian.chadd@gmail.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 CF4C3D33 for ; Thu, 3 Sep 2015 21:42:45 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by mailman.ysv.freebsd.org (Postfix) id CE21B9C9E63; Thu, 3 Sep 2015 21:42:45 +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 CDB2E9C9E62 for ; Thu, 3 Sep 2015 21:42:45 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-ig0-x230.google.com (mail-ig0-x230.google.com [IPv6:2607:f8b0:4001:c05::230]) (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 9A56FD32; Thu, 3 Sep 2015 21:42:45 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by igcrk20 with SMTP id rk20so1504445igc.1; Thu, 03 Sep 2015 14:42:45 -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=o8MTDSc9N9CYKDVbTP83qJfwW0Xe9j9kncckSVTb1VQ=; b=Yv/KsjbkuTdoDka+zh7Ua6svciGqNzBBulKLBQSpasZu1d88aI8jTSgYU4x5sa6+Q7 oUgy002VDBFo25kTXtLE+pOxC26sBefdNYfIGN2vB2sVcVZzwx4htA9EGbyyNAZU08dH jd6sZGdKH2MBevKra32jPElddR1IDB3XNij942szokTAcPTg+M4sq1nXq4KM7f7F7QAZ VE6sreWe2KJy7Bhb9RdvymMJ2dx3ga6Up6UE51vbaGWN4HR5a95/WUP8z0Dz27RUxzZT SoNC8K1tCRyVboTPCJEyjPoKV5bqYYaqKGPEpnAYxb0fshvUESjS8DciS4o6BPYzT1aH LoTw== MIME-Version: 1.0 X-Received: by 10.50.49.101 with SMTP id t5mr639070ign.61.1441316565067; Thu, 03 Sep 2015 14:42:45 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.28.208 with HTTP; Thu, 3 Sep 2015 14:42:45 -0700 (PDT) In-Reply-To: References: <20150901112043.GB1023@glebius.int.ru> <20150902060324.GF1023@glebius.int.ru> Date: Thu, 3 Sep 2015 14:42:45 -0700 X-Google-Sender-Auth: Sps5yrZOqoqVs2WXb7VrAzPaomg Message-ID: Subject: Re: mbufq-less iwn(4) From: Adrian Chadd To: Andriy Voskoboinyk Cc: Gleb Smirnoff , Lawrence Stewart , "net@freebsd.org" Content-Type: text/plain; charset=UTF-8 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: Thu, 03 Sep 2015 21:42:46 -0000 It's fixed in -head. I should close that. -a On 3 September 2015 at 07:11, Andriy Voskoboinyk wrote: >> Adrian, >> >> On Tue, Sep 01, 2015 at 12:33:53PM -0700, Adrian Chadd wrote: >> A> We have to do mbuf queues in drivers for wifi, because of 11n >> A> aggregation. So on one hand we want to have if_transmit() apply >> A> backpressure through the stack, but there's also going to be some >> A> buffering. :P >> >> No, that's not because of 11n aggregation. That's a remnant of >> ifnet ifqueue. Note that I'm speaking about queueing in drivers, >> not in net80211 stack. Look at the iwn patch, it doesn't remove >> any functionality except of enqueueing and dequeueing. >> >> Look at your own ath(4) - there is no software queue there already :) >> >> A> I'd like to see that for ic_transmit(). >> A> >> A> Other thing - ic_transmit() also needs to handle fragments, like I do >> A> with ath. Ie, handing it a list of packets is actually a list of >> A> 802.11 fragments, rather than separate MPDUs. >> A> >> A> Another thing - we're modifying the mbufs (adding 802.11 data to it) >> A> before we pass them to the driver, and if the driver fails to >> A> transmit, we can't just pass it back up the net80211 stack to the tcp >> A> or udp layer.. >> >> Sure, stack probably would need to strip the data. Anyway, that's >> a future task. >> > > What about https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193569 ?