Return-path: Received: from mail-wm0-f43.google.com ([74.125.82.43]:35818 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750854AbcC3JWx convert rfc822-to-8bit (ORCPT ); Wed, 30 Mar 2016 05:22:53 -0400 Received: by mail-wm0-f43.google.com with SMTP id 191so81400287wmq.0 for ; Wed, 30 Mar 2016 02:22:52 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <56FAA518.2000805@candelatech.com> References: <1458898743-21118-1-git-send-email-michal.kazior@tieto.com> <56FAA518.2000805@candelatech.com> Date: Wed, 30 Mar 2016 11:22:51 +0200 Message-ID: (sfid-20160330_112257_434853_58AF3996) Subject: Re: [RFC] ath10k: implement dql for htt tx From: Michal Kazior To: Ben Greear Cc: Dave Taht , "ath10k@lists.infradead.org" , linux-wireless , make-wifi-fast@lists.bufferbloat.net, "codel@lists.bufferbloat.net" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 29 March 2016 at 17:54, Ben Greear wrote: > On 03/29/2016 12:49 AM, Michal Kazior wrote: > >>> if you are getting a pure codel result of 160ms, that means the >>> implementation is broken. But I think (after having read your >>> description twice), the baseline result today of 160ms of queuing was >>> with a fq_codel *qdisc* doing the work on top of huge buffers, >> >> >> Yes. The 160ms is with fq_codel qdisc with ath10k doing DQL at 6mbps. >> Without DQL ath10k would clog up all tx slots (1424 of them) with >> frames. At 6mbps you typically want/need a handful (5-10) of frames to >> be queued. > > > Have you actually verified you can use all tx slots? It works in most cases. I guess you're suspecting some of your tx(flushing?) problems might be induced by overcommiting? > The way the > firmware uses it's tx buffers I think you may not be able to actually > do that...and in practice, you will get a lot fewer usable tx-buffers > than configured.... Could be, e.g. I'm aware management frames are kind of a special case in recent firmware revisions. What would/do you expect firmware would/will do when we overcommit? The driver does advertise number of HTT tx slots so I would expect it to work fine if it didn't crash during boot. Michał