From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from s3.sipsolutions.net ([5.9.151.49]:53189 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932569AbbCQKDz (ORCPT ); Tue, 17 Mar 2015 06:03:55 -0400 Message-ID: <1426586632.1985.5.camel@sipsolutions.net> (sfid-20150317_110404_469271_13AF6EE2) Subject: Re: [PATCH] mac80211: minstrel_ht: fix rounding issue in MCS duration calculation From: Johannes Berg To: Felix Fietkau Cc: linux-wireless@vger.kernel.org, karl.beldan@gmail.com Date: Tue, 17 Mar 2015 11:03:52 +0100 In-Reply-To: <1426240484-37307-1-git-send-email-nbd@openwrt.org> References: <1426240484-37307-1-git-send-email-nbd@openwrt.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2015-03-13 at 10:54 +0100, Felix Fietkau wrote: > On very high MCS bitrates, the calculated duration of rates that are > next to each other can be very imprecise, due to the small packet size > used as reference (1200 bytes). > This is most visible in VHT80 nss=2 MCS8/9, for which minstrel shows the > same throughput when the probability is also the same. This leads to a > bad rate selection for such rates. > > Fix this issue by introducing an average A-MPDU size factor into the > calculation. Applied. johannes