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=-0.8 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 EE38AC43219 for ; Fri, 26 Apr 2019 07:07:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE0B5206BA for ; Fri, 26 Apr 2019 07:07:10 +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="g8swHKY+"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="RtINaDOd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725984AbfDZHHJ (ORCPT ); Fri, 26 Apr 2019 03:07:09 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43058 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725877AbfDZHHJ (ORCPT ); Fri, 26 Apr 2019 03:07:09 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 1C9A160736; Fri, 26 Apr 2019 07:07:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1556262428; bh=24kT1HnRZjrCbMcgQA4CP+mbQo8uvplZg4zehp6YyBU=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=g8swHKY+LBKS5B4yD29KAg3i8Zu0GJOm5o5IaxbD3tBLQYCnZcG4WgGnZxsogrB58 YKa7PO8oRYlYIOunFgGIw8+KMPyiFmAPu4O6IF0oP/rZSHzAlW23T53Z5GQfCPNHvC 6Vw9ZhKGxVXCkiSAX3+gjUTr1x8bDBqS6rEsE96U= Received: from potku.adurom.net (88-114-240-156.elisa-laajakaista.fi [88.114.240.156]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: kvalo@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 332176053B; Fri, 26 Apr 2019 07:07:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1556262427; bh=24kT1HnRZjrCbMcgQA4CP+mbQo8uvplZg4zehp6YyBU=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=RtINaDOd40ILPnT6/GX8bxtvtnwfxJL/PI0JkiP4IbmiCXvv4P0epORT/xaiB1H9i WEvQpDtaHWabrNQTUqSZ+opzOqQRbaSedZeeywiO+gkYShwOGXnVTuFkT3yM1HTaF+ ftPmemLH8qY/dQIXoxrg3+VfYKCcbWFGuukKH/R0= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 332176053B Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=kvalo@codeaurora.org From: Kalle Valo To: Erik Stromdahl Cc: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= , linux-wireless@vger.kernel.org, ath10k@lists.infradead.org, yiboz@codeaurora.org Subject: Re: [PATCH] ath10k: remove iteration in wake_tx_queue References: <20190327162906.6010-1-erik.stromdahl@gmail.com> <87bm1qq92j.fsf@toke.dk> <8772dfe6-3f52-05ca-f55a-b7eae14fa7ac@gmail.com> <87imvdu5u8.fsf@toke.dk> Date: Fri, 26 Apr 2019 10:07:03 +0300 In-Reply-To: (Erik Stromdahl's message of "Wed, 17 Apr 2019 15:29:41 +0200") Message-ID: <87sgu5utwo.fsf@kamboji.qca.qualcomm.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Erik Stromdahl writes: > On 4/16/19 9:07 PM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> Erik Stromdahl writes: >> >>> On 4/1/19 1:05 PM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >>>> 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_l= ock) >>>>> 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 he= ld >>>> in mac80211? >>>> >>>> -Toke >>>> >>> Hi Toke, >>> >>> I am not aware of these patches. Can you please point them out for me? >> >> They've already been merged. Commits dcec1d9bc8a7 and 7ef769459f14 in >> mac80211-next :) >> >> -Toke >> > > I see. I am using the ath tree and I couldn't find them there. > I can cherry-pick them to my own tree and try them out > (or wait until Kalle updates ath.git). It will take a while before these commits trickle down to ath-next branch, most likely after v5.2-rc1 is released. --=20 Kalle Valo