From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sipsolutions.net (s3.sipsolutions.net [168.119.38.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3A8C52ED42 for ; Tue, 8 Sep 2026 14:09:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.38.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788876571; cv=none; b=kGh/mPrXrUgzvMDsgozeDFOnGvivrkB8wZpmmVlU57+SZ0T1K2l30Jmyu2DBcAsscEzl+Lo/1ybZ7QrpmF76YxV3GCPVpuDFSTtvaNoYuueA1FpARk1haLibXyDenS9q+J7XIbMQDlrdZ1f03qKMoxZztunC1CtSfCZ3dY0qXnU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788876571; c=relaxed/simple; bh=f6cefW1iNeuWJbi6SCsNRCtKbgoCxvp7qEC++5yYsC4=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=HDnQmoV27WjJNjhFtPrQUYchhCkY24WNyXJUNdvI5hyuKSI2jydtsM48AVl2tqus65LaMcrlh2yNCN/i+w4OvIJlJu4N7FsRgf8E/q0jeUOzN9X1FJH+C4Z1+L1oI1Yf5qQywexn/2Ixm185dLUcdHkpF4l2ybvJ3iVXwIShrqM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net; spf=pass smtp.mailfrom=sipsolutions.net; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b=oKXNjem6; arc=none smtp.client-ip=168.119.38.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=permerror header.from=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sipsolutions.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sipsolutions.net header.i=@sipsolutions.net header.b="oKXNjem6" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=f6cefW1iNeuWJbi6SCsNRCtKbgoCxvp7qEC++5yYsC4=; t=1788876558; x=1790086158; b=oKXNjem6jK4r1E/SxuuOYlvX/0n+0iv36X3Ib50HyHq2zj/ o4mb2Qp9Fp7kFDf8Byp4rXftYiDOK8P2Wm5oKcoYpQndn8qFYT2J9ETAkOcvZUG3XzC38nRv47T8K ZXUHhXUg3Uyu++QrRugskpSlixgNN/wLq93JIIrLo/4xtlg4w+vN+g2zULFDrKUxZ5YDUVhcuKrNj O2LdffuJ88SH/q23Ue33iqC3cR+OyY2jCl5Yp12TDEU0ToiGhvxrBhnFOOyETi1vnlukCvCx6T/0D 3gwGB6bBuAcT+StlnkjyxViBviiTWBcnTX6KiZ5mbqUT7gOvwKNt9sjUcaGo8esA==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__ECDSA_SECP256R1_SHA256__AES_256_GCM:256) (Exim 4.98.2) (envelope-from ) id 1x3wVX-00000006EAg-2THg; Tue, 08 Sep 2026 16:09:07 +0200 Message-ID: <702d4fd96837e42ac5d7491e3001ef6eae09b282.camel@sipsolutions.net> Subject: Re: [PATCH] wifi: mac80211: keep the TXQ scheduling round number across a closed round From: Johannes Berg To: Julius Bairaktaris Cc: toke@toke.dk, nbd@nbd.name, linux-wireless@vger.kernel.org Date: Tue, 08 Sep 2026 16:09:06 +0200 In-Reply-To: <20260908135224.754049-1-julius@bairaktaris.de> (sfid-20260908_155227_340708_827E0581) References: <20260908135224.754049-1-julius@bairaktaris.de> (sfid-20260908_155227_340708_827E0581) Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-1.fc44) Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-malware-bazaar: not-scanned On Tue, 2026-09-08 at 15:52 +0200, Julius Bairaktaris wrote: > ieee80211_txq_schedule_start() sets local->schedule_round[ac] to 0 when > the access category is over its airtime limit, so that > ieee80211_next_txq() serves nothing until a round passes the check > again. That round is then numbered 1. ieee80211_next_txq() ends a round > when it reaches a txq whose schedule_round equals the current number, > so a txq served in a round numbered 1 is skipped in the next round > numbered 1 as well. >=20 > Where the airtime queue limit binds, closed and open rounds alternate, > so half of the rounds that could refill the queue return nothing. >=20 > Track whether a round is open in its own flag and leave the round > number alone. Checking the limit in ieee80211_next_txq() instead would > walk the active list once per txq served rather than once per round. >=20 > Measured on an IPQ8074 AP with ath11k advertising AQL through the > series "wifi: ath11k: airtime queue limits, fairness and a driver TXQ > scheduler", one 1x1 VHT80 station, BE aql_txq_limit 500/1000 us, 20 s > runs, three interleaved runs per arm, the skipped selections counted > where ieee80211_next_txq() ends the round. With a TCP download > forwarded from a wired host, 4227, 4195 and 4268 selections are skipped > per run without this change and 15, 24 and 41 with it, at 99 to 100 > Mbit/s either way: the network stack's arrivals start rounds often > enough to cover the loss. With the download generated on the access > point, where TCP small queues pace the arrivals, the skipped rounds are > the ones that would have refilled the queue: 35.6, 44.4 and 42.8 Mbit/s > without this change and 94.7, 94.6 and 95.0 with it. >=20 For the record - one last time - since you keep writing everything with an LLM I will keep dropping it unread. johannes