From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A878C43441 for ; Wed, 10 Oct 2018 04:52:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02CFE2085B for ; Wed, 10 Oct 2018 04:52:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="gAqO6NGP"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="mMdnO77y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 02CFE2085B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-wireless-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbeJJMM6 (ORCPT ); Wed, 10 Oct 2018 08:12:58 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48128 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726647AbeJJMM5 (ORCPT ); Wed, 10 Oct 2018 08:12:57 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 5002660C4B; Wed, 10 Oct 2018 04:52:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1539147158; bh=iOzgbAVzAIcSWA+ffRzZN/iGg+Lgn5t3ojuyNHUFy2I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gAqO6NGPkp9guRP95e918t7h3zf1Ua6Kto5TempWJsJojAKGEtDhmY2jg/pxLtrW1 9ejX1p/3hqXB5/lXwD4xTfMT+VyYz8GvYouMTeADnc49Q6ImWT9HqTtH5VUTHP7+GX W6yQceij9w7jwRSPsJ8oRyA7pmJ7YwqT3G9L3c0A= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id AF4FB60769; Wed, 10 Oct 2018 04:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1539147157; bh=iOzgbAVzAIcSWA+ffRzZN/iGg+Lgn5t3ojuyNHUFy2I=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mMdnO77ye/jxDCHMK+UQrUJ7r06ZYgr18ODAa3OsCm+pLBa/xNUbPxwFYzS7Gcx/f jpn2YQy1IFnBKvCumLimpHiV1fHEGCB/fknDnPq9s45omAgpffChmOSe3G3l79KDiz e0SZenzfzj4kNBVw/0Kw5u/tXap0Cpy3Z2m+pYbU= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Tue, 09 Oct 2018 21:52:37 -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 Subject: Re: [PATCH RFC v5 3/4] mac80211: Add airtime accounting and scheduling to TXQs In-Reply-To: <153908837900.9471.5394468800857658136.stgit@alrua-kau> References: <153908805217.9471.9290979918041653328.stgit@alrua-kau> <153908837900.9471.5394468800857658136.stgit@alrua-kau> Message-ID: X-Sender: rmanohar@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On 2018-10-09 05:32, Toke Høiland-Jørgensen wrote: > This adds airtime accounting and scheduling to the mac80211 TXQ > scheduler. A new callback, ieee80211_sta_register_airtime(), is added > that drivers can call to report airtime usage for stations. > > When airtime information is present, mac80211 will schedule TXQs > (through ieee80211_next_txq()) in a way that enforces airtime fairness > between active stations. This scheduling works the same way as the > ath9k > in-driver airtime fairness scheduling. If no airtime usage is reported > by the driver, the scheduler will default to round-robin scheduling. > > For drivers that don't control TXQ scheduling in software, a new API > function, ieee80211_txq_may_transmit(), is added which the driver can > use > to check if the TXQ is eligible for transmission, or should be > throttled to > enforce fairness. Calls to this function must also be enclosed in > ieee80211_txq_schedule_{start,end}() calls to ensure proper locking. > TXQs > that are throttled by ieee802111_txq_may_transmit() will be woken up > again > by a check added to the ieee80211_wake_txqs() tasklet. > Toke, I am observing soft lockup issues again with this new series while running traffic with 50 clients. I am continuing testing with earlier series along with snippet I shared. When driver operates in pull-mode, throttled txqs are marked and refilled in airtime_tasklet. This is causing major throughput drops and packet loss and I am suspecting the latency in replenishing deficit. Whereas in push-mode or in ath9k model, refill happens quicker at every packet indication as well as tx completion. I am planning to get rid of tasklet completely as it is only meant for pull-mode. It would be better to refill in may_transmit() itself. -Rajkumar