From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lf1-f65.google.com ([209.85.167.65]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hAulR-0002EZ-8f for ath10k@lists.infradead.org; Mon, 01 Apr 2019 11:06:07 +0000 Received: by mail-lf1-f65.google.com with SMTP id a6so5974799lfl.5 for ; Mon, 01 Apr 2019 04:06:03 -0700 (PDT) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= Subject: Re: [PATCH] ath10k: remove iteration in wake_tx_queue In-Reply-To: <20190327162906.6010-1-erik.stromdahl@gmail.com> References: <20190327162906.6010-1-erik.stromdahl@gmail.com> Date: Mon, 01 Apr 2019 13:05:56 +0200 Message-ID: <87bm1qq92j.fsf@toke.dk> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Erik Stromdahl , kvalo@qca.qualcomm.com, linux-wireless@vger.kernel.org, ath10k@lists.infradead.org Cc: yiboz@codeaurora.org Erik Stromdahl writes: > Iterating the TX queue and thereby dequeuing all available packets in the > queue could result in performance penalties on some SMP systems. > > The reason for this is most likely that the per-ac lock (active_txq_lock) > in mac80211 will be held by the CPU iterating the current queue. > > This will lock up other CPUs trying to push new messages on the TX > queue. > > Instead of iterating the queue we fetch just one packet at the time, > resulting in minimal starvation of the other CPUs. Did you test this with Felix' patches reducing the time the lock is held in mac80211? -Toke _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k