From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org (smtp.codeaurora.org [198.145.29.96]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 3CE2F3B25D for ; Tue, 23 Aug 2016 02:59:49 -0400 (EDT) Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2FB9A61C8C; Tue, 23 Aug 2016 06:59:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from potku.adurom.net (a88-115-185-251.elisa-laajakaista.fi [88.115.185.251]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: kvalo@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id E12DD61C78; Tue, 23 Aug 2016 06:59:45 +0000 (UTC) From: Kalle Valo To: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= Cc: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net, ath9k-devel@lists.ath9k.org, Tim Shepard , Felix Fietkau References: <20160706193417.13080-1-toke@toke.dk> <20160805160346.10545-1-toke@toke.dk> <87mvk44xmt.fsf@purkki.adurom.net> <87bn0k4w4d.fsf@toke.dk> <87fupwvisn.fsf@kamboji.qca.qualcomm.com> <871t1g4thz.fsf@toke.dk> In-Reply-To: <871t1g4thz.fsf@toke.dk> ("Toke =?utf-8?Q?H=C3=B8iland-J?= =?utf-8?Q?=C3=B8rgensen=22's?= message of "Mon, 22 Aug 2016 19:13:12 +0200") Message-ID: <877fb8ug0x.fsf@kamboji.qca.qualcomm.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Mon, 28 Nov 2016 08:47:10 -0500 Subject: Re: [Make-wifi-fast] [PATCH v4] ath9k: Switch to using mac80211 intermediate software queues. X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Date: Tue, 23 Aug 2016 06:59:49 -0000 X-Original-Date: Tue, 23 Aug 2016 09:59:42 +0300 X-List-Received-Date: Tue, 23 Aug 2016 06:59:49 -0000 Toke H=C3=B8iland-J=C3=B8rgensen writes: >>>> This is great work but due to the regressions I'm not sure if this >>>> will be ready for 4.9. To get more testing time I wonder if we should >>>> wait for 4.10? IMHO applying this in the end of the cycle is too risky >>>> and we should try to maximise the time linux-next by applying this >>>> just after -rc1 is released. >>>> >>>> Thoughts? >>> >>> Well, now that we understand what is causing the throughput regressions, >>> fixing them should be fairly straight forward (yeah, famous last words, >>> but still...). I already have a patch for the fast path and will go poke >>> at the slow path next. It'll probably require another workaround or two, >>> so I guess it won't be the architecturally clean ideal solution; but it >>> would make it possible to have something that works for 4.9 and then >>> iterate for a cleaner design for 4.10. >> >> But if we try to rush this to 4.9 it won't be in linux-next for long. We >> are now in -rc3 and let's say that the patches are ready to apply in two >> weeks. That would leave us only two weeks of -next time before the merge >> window, which I think is not enough for a controversial patch like this >> one. There might be other bugs lurking which haven't been found yet. > > What, other hidden bugs? Unpossible! :) Yeah, right ;) > Would it be possible to merge the partial solution (which is ready now, > basically) and fix the slow path in a separate patch later? What do you mean with partial solution? You mean ath9k users would suffer from regressions until they are fixed? We can't do that. > (Just spit-balling here; I'm still fairly new to this process. But I am > concerned that we'll hit a catch-22 where we can't get wider testing > before it's "ready" and we can't prove that it's "ready" until we've had > wider testing...) I understand your point, but I don't want to rush this to 4.9 and then start getting lots of bug reports and eventually forced to revert it. If we just found a new serious regression the chances are that there are more lurking somewhere and this patch is just not ready yet. --=20 Kalle Valo