From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1b29fd-0007OR-Ip for ath10k@lists.infradead.org; Mon, 16 May 2016 03:58:18 +0000 MIME-Version: 1.0 Date: Mon, 16 May 2016 09:27:54 +0530 From: Rajkumar Manoharan Subject: Re: ath10k performance, master branch from 20160407 In-Reply-To: References: <1460129643950.46282@qti.qualcomm.com> <1460174525702.66744@qti.qualcomm.com> <1460905574286.42282@qti.qualcomm.com> <87k2jtk3wt.fsf@kamboji.qca.qualcomm.com> Message-ID: <64e989f9150dadda9f02e6c2e728552a@codeaurora.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Roman Yeryomin Cc: "Valo, Kalle" , Michal Kazior , ath10k@lists.infradead.org, "Manoharan, Rajkumar" On 2016-05-16 04:29, Roman Yeryomin wrote: > On 9 May 2016 at 15:26, Michal Kazior wrote: >> Hi Roman, >> >> On 22 April 2016 at 19:05, Roman Yeryomin >> wrote: >>> On 19 April 2016 at 18:35, Valo, Kalle >>> wrote: >>>> Michal Kazior writes: >>>> >>>>> On 19 April 2016 at 09:31, Roman Yeryomin >>>>> wrote: >>>>>> On 19 April 2016 at 08:28, Michal Kazior >>>>>> wrote: >>>>>> >>>>>>> If my hunch is right there's no easy (and proper) fix for that >>>>>>> now. >>>>>>> >>>>>>> One of the patchset patches (ath10k: implement wake_tx_queue) >>>>>>> starts >>>>>>> to use mac80211 software queuing. This introduces extra induced >>>>>>> latency and I'm guessing it results in fill-in-then-drain >>>>>>> sequences in >>>>>>> some cases which end up being long enough to make fq_codel_drop >>>>>>> more >>>>>>> work than normal. >>>>>>> >>>>>>> This is required for other changes and MU-MIMO performance >>>>>>> improvements so this patch can't be removed. >>>>>> >>>>>> But qca988x doesn't support MU-MIMO, AFAIK. >>>>> >>>>> Correct. >>>>> >>>>> >>>>>> Can this be made chip dependent? >>>>> >>>>> I guess it could but it'd arguably make the driver more complex and >>>>> harder to maintain. What we want is a long-term fix, not a >>>>> short-term >>>>> one. >>>> >>>> But we should never go backwards and TCP dropping from 750 Mbps to >>>> ~550 >>>> Mbps is a huge drop, so this is not ok. We have to do something to >>>> fix >>>> this, be it reverting the wake_tx_queue support, somehow disabling >>>> it by >>>> default or something. >>> >>> I would agree with Kalle here. This looks like very serious >>> regression. >>> But I'm afraid I can only help with testing here. >> >> Can you give the following patch a try, please? I didn't get to >> reproduce your problem on a real AP135/AP152 board and instead tried >> to simulate a slow uni-proc system via KVM and cooling_device in >> sysfs. The patch does improve things in this synthetic setup for me. >> >> http://lists.infradead.org/pipermail/ath10k/2016-May/007526.html >> > > Unfortunately doesn't seem to make any difference at all (really, if > there is, it's less than 10Mbps). > Please see this thread also: > https://lists.openwrt.org/pipermail/openwrt-devel/2016-May/041445.html > That is with your and Eric's patch applied. > Roman, Can you please try without registering wake_tx_queue callback? software queuing is needed for devices that supports peer-flow-control. diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 6829a08638b2..5df904169ded 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -7313,7 +7313,6 @@ ath10k_mac_op_switch_vif_chanctx(struct ieee80211_hw *hw, static const struct ieee80211_ops ath10k_ops = { .tx = ath10k_mac_op_tx, - .wake_tx_queue = ath10k_mac_op_wake_tx_queue, .start = ath10k_start, .stop = ath10k_stop, .config = ath10k_config, -Rajkumar _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k