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 52E413CB38 for ; Fri, 28 Sep 2018 05:44:20 -0400 (EDT) Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 9673760B13; Fri, 28 Sep 2018 09:44:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1538127859; bh=ZPRI8yQpZjCyHxkpuas/KeMPtPoWnO1lSpftX03QE+E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=F6uP+3pawFrnJ2kbaUJNvDpbUtLgD3MUVRjSz+2w7G9R8T/vJZ/F18YrcGWoT7DLw LoqL0pCQM8rj354cUsg4lFKzRyGaWRniU2P3gNW0KeJksqh4wrYAXAfaVNdflix989 8wk4/9R2i3C3uK14Em+HZi4Td7zXz+Fg1aPSO3io= 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=-2.7 required=2.0 tests=ALL_TRUSTED,BAYES_00, DKIM_INVALID,DKIM_SIGNED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id 3E2AC60274; Fri, 28 Sep 2018 09:44:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1538127859; bh=ZPRI8yQpZjCyHxkpuas/KeMPtPoWnO1lSpftX03QE+E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=F6uP+3pawFrnJ2kbaUJNvDpbUtLgD3MUVRjSz+2w7G9R8T/vJZ/F18YrcGWoT7DLw LoqL0pCQM8rj354cUsg4lFKzRyGaWRniU2P3gNW0KeJksqh4wrYAXAfaVNdflix989 8wk4/9R2i3C3uK14Em+HZi4Td7zXz+Fg1aPSO3io= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Fri, 28 Sep 2018 02:44:19 -0700 From: Rajkumar Manoharan To: =?UTF-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Cc: linux-wireless@vger.kernel.org, make-wifi-fast@lists.bufferbloat.net, Felix Fietkau , Kan Yan , linux-wireless-owner@vger.kernel.org In-Reply-To: <7ba8513b0ec5a7c35b396c7739fc2d7d@codeaurora.org> References: <153711966150.9231.13481453399723518107.stgit@alrua-x1> <153711973134.9231.18038849900399644494.stgit@alrua-x1.karlstad.toke.dk> <826b6251746ee4d280d532f4ecdc5aa3@codeaurora.org> <87pnx0haud.fsf@toke.dk> <8f7145bf5abe50194bced025a5e739b9@codeaurora.org> <863bc54fbf04441d38dd53f523300a7e@codeaurora.org> <93015743-5D16-4D79-948F-E2F46CF2450A@toke.dk> <7ba8513b0ec5a7c35b396c7739fc2d7d@codeaurora.org> Message-ID: X-Sender: rmanohar@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Subject: Re: [Make-wifi-fast] [PATCH RFC v4 3/4] mac80211: Add airtime accounting and scheduling to TXQs 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: , X-List-Received-Date: Fri, 28 Sep 2018 09:44:20 -0000 On 2018-09-28 02:27, Rajkumar Manoharan wrote: > On 2018-09-28 00:51, Toke Høiland-Jørgensen wrote: >> On 28 September 2018 07:29:03 CEST, Rajkumar Manoharan >> wrote: >>> On 2018-09-26 17:09, Rajkumar Manoharan wrote: >>>> On 2018-09-26 02:22, Toke Høiland-Jørgensen wrote: >>>>> Rajkumar Manoharan writes: >>> >>>> :( Yeah... I got confused with attached soft lockup in ARM platform. >>>> >>> Toke, >>> >>> Cause for the soft lockup exposed in multi client scenario is due to >>> mixed order of fq_lock and active_txqs_lock. In wake_tx_queue or >>> push_pending >>> case, driver acquires active_txq_lock first by schedule_start and >>> followed by >>> fq_lock in tx_dequeue. The same order should be maintained in sta >>> cleanup. >>> Below change fixed the issue. >> >> Ah, great find! I'll fold this into the next version, thanks! >> > > One more thing. As I mentioned earlier, scheduling wake_txqs_tasklet > is heavy load and causing random rcu stall issue. Hence I added > another API to schedule throttled txqs once for all. Also I did > a cleanup in kick_airtime by traversing list only once. With these > changes I don't see rcu stall issue. Please review and fold them as > well. > Correction in patch. new API schedule kick_aitime tasklet not wake_txq_tasklet. +void ieee80211_txq_schedule_throttled(struct ieee80211_hw *hw) +{ + struct ieee80211_local *local = hw_to_local(hw); + + tasklet_schedule(&local->kick_airtime); +} -Rajkumar