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=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 27DACC6379D for ; Mon, 23 Nov 2020 12:26:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF52B20888 for ; Mon, 23 Nov 2020 12:26:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="q/pAN/df" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730105AbgKWM0J (ORCPT ); Mon, 23 Nov 2020 07:26:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:35928 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730098AbgKWM0I (ORCPT ); Mon, 23 Nov 2020 07:26:08 -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 0F34920728; Mon, 23 Nov 2020 12:26:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1606134367; bh=fMDFc7sls7u6Zpyw/rSEiFHR2PZDRH/WfP6ox+BkHSg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q/pAN/dfyWNKsYPmqzNwO+D2NbW0kdR5pOAJi7rKtqsaRE5QPHIu10rM7zCZ7WMnp JKDASvHgNR4ZBdoFnsuWHanMcuCaotTm8c7a76Bbu6854aD9KgTj/XUwcSBZIFjkud upcC1eqsMIYThEh6daydbVfbEI5VbhzRXnmKXG7o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Felix Fietkau , Johannes Berg Subject: [PATCH 4.9 43/47] mac80211: minstrel: remove deferred sampling code Date: Mon, 23 Nov 2020 13:22:29 +0100 Message-Id: <20201123121807.641024414@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201123121805.530891002@linuxfoundation.org> References: <20201123121805.530891002@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 @@ -287,12 +287,6 @@ 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); @@ -366,7 +360,7 @@ minstrel_get_rate(void *priv, struct iee #endif 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; @@ -375,7 +369,6 @@ 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) { @@ -400,19 +393,8 @@ 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; @@ -432,6 +414,7 @@ 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 @@ -105,7 +105,6 @@ 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;