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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 004CFC63798 for ; Mon, 23 Nov 2020 13:25:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6E3F204EC for ; Mon, 23 Nov 2020 13:25:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nBMC+rdv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730616AbgKWMdO (ORCPT ); Mon, 23 Nov 2020 07:33:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:44544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730614AbgKWMdK (ORCPT ); Mon, 23 Nov 2020 07:33:10 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D7E9D20888; Mon, 23 Nov 2020 12:33:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134788; bh=KSX0GOJAIGf/XPCwJh5SbZHN4b3oQ1XwQefD9h4Ag9g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nBMC+rdv9UkpP4i+efxFrR9vdwNgWgEoh8ej1LWDHPFdlNKPZrOEhP2NSoMbHYK8y QTVq+Fs4ykW6fPB/OMMXFd1HfX2wBBRbslC2Y5TTu43GNteag6EdIZkZCwWzmAh6E8 vQhyeDw2cUB108/Gz24MXUz3nWLYfPKHF9//YcZU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Felix Fietkau , Johannes Berg Subject: [PATCH 4.19 83/91] mac80211: minstrel: remove deferred sampling code Date: Mon, 23 Nov 2020 13:22:43 +0100 Message-Id: <20201123121813.358386193@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121809.285416732@linuxfoundation.org> References: <20201123121809.285416732@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Felix Fietkau commit 4fe40b8e1566dad04c87fbf299049a1d0d4bd58d upstream. Deferring sampling attempts to the second stage has some bad interactions with drivers that process the rate table in hardware and use the probe flag to indicate probing packets (e.g. most mt76 drivers). On affected drivers it can lead to probing not working at all. If the link conditions turn worse, it might not be such a good idea to do a lot of sampling for lower rates in this case. Fix this by simply skipping the sample attempt instead of deferring it, but keep the checks that would allow it to be sampled if it was skipped too often, but only if it has less than 95% success probability. Also ensure that IEEE80211_TX_CTL_RATE_CTRL_PROBE is set for all probing packets. Cc: stable@vger.kernel.org Fixes: cccf129f820e ("mac80211: add the 'minstrel' rate control algorithm") Signed-off-by: Felix Fietkau Link: https://lore.kernel.org/r/20201111183359.43528-2-nbd@nbd.name Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/rc80211_minstrel.c | 25 ++++--------------------- net/mac80211/rc80211_minstrel.h | 1 - 2 files changed, 4 insertions(+), 22 deletions(-) --- a/net/mac80211/rc80211_minstrel.c +++ b/net/mac80211/rc80211_minstrel.c @@ -289,12 +289,6 @@ minstrel_tx_status(void *priv, struct ie mi->r[ndx].stats.success += success; } - if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) - mi->sample_packets++; - - if (mi->sample_deferred > 0) - mi->sample_deferred--; - if (time_after(jiffies, mi->last_stats_update + (mp->update_interval * HZ) / 1000)) minstrel_update_stats(mp, mi); @@ -373,7 +367,7 @@ minstrel_get_rate(void *priv, struct iee return; delta = (mi->total_packets * sampling_ratio / 100) - - (mi->sample_packets + mi->sample_deferred / 2); + mi->sample_packets; /* delta < 0: no sampling required */ prev_sample = mi->prev_sample; @@ -382,7 +376,6 @@ minstrel_get_rate(void *priv, struct iee return; if (mi->total_packets >= 10000) { - mi->sample_deferred = 0; mi->sample_packets = 0; mi->total_packets = 0; } else if (delta > mi->n_rates * 2) { @@ -407,19 +400,8 @@ minstrel_get_rate(void *priv, struct iee * rate sampling method should be used. * Respect such rates that are not sampled for 20 interations. */ - if (mrr_capable && - msr->perfect_tx_time > mr->perfect_tx_time && - msr->stats.sample_skipped < 20) { - /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark - * packets that have the sampling rate deferred to the - * second MRR stage. Increase the sample counter only - * if the deferred sample rate was actually used. - * Use the sample_deferred counter to make sure that - * the sampling is not done in large bursts */ - info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; - rate++; - mi->sample_deferred++; - } else { + if (msr->perfect_tx_time < mr->perfect_tx_time || + msr->stats.sample_skipped >= 20) { if (!msr->sample_limit) return; @@ -439,6 +421,7 @@ minstrel_get_rate(void *priv, struct iee rate->idx = mi->r[ndx].rix; rate->count = minstrel_get_retry_count(&mi->r[ndx], info); + info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; } --- a/net/mac80211/rc80211_minstrel.h +++ b/net/mac80211/rc80211_minstrel.h @@ -98,7 +98,6 @@ struct minstrel_sta_info { u8 max_prob_rate; unsigned int total_packets; unsigned int sample_packets; - int sample_deferred; unsigned int sample_row; unsigned int sample_column;