From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nbd.name ([46.4.11.11]:45630 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751377Ab3CJXde (ORCPT ); Sun, 10 Mar 2013 19:33:34 -0400 Message-ID: <513D184B.2000805@openwrt.org> (sfid-20130311_003352_540321_A0A0DFD5) Date: Mon, 11 Mar 2013 00:33:31 +0100 From: Felix Fietkau MIME-Version: 1.0 To: Karl Beldan CC: Johannes Berg , linux-wireless , Karl Beldan Subject: Re: [PATCH v2 1/2] mac80211: get the rates masks from the txrc in rate_control_get_rate References: <1362421635-28008-1-git-send-email-karl.beldan@gmail.com> <1362427924.21028.42.camel@jlt4.sipsolutions.net> <20130304204541.GA8819@gobelin> <5135F327.4000408@openwrt.org> <20130310221627.GA3824@gobelin> <513D08B5.1030007@openwrt.org> <20130310230600.GC3824@gobelin> In-Reply-To: <20130310230600.GC3824@gobelin> Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2013-03-11 12:06 AM, Karl Beldan wrote: > On Sun, Mar 10, 2013 at 11:27:01PM +0100, Felix Fietkau wrote: >> On 2013-03-10 11:16 PM, Karl Beldan wrote: >> > On Tue, Mar 05, 2013 at 02:29:11PM +0100, Felix Fietkau wrote: >> >> On 2013-03-04 9:45 PM, john wrote: >> >> > On Mon, Mar 04, 2013 at 09:12:04PM +0100, Johannes Berg wrote: >> >> >> On Mon, 2013-03-04 at 19:27 +0100, Karl Beldan wrote: >> >> >> > From: Karl Beldan >> >> >> > >> >> >> > Currently it gets it from the sdata. This uses and updates the ad-hoc >> >> >> > masks of the ieee80211_tx_rate_control instead of copying them. >> >> >> >> >> >> Is there any need to update them? >> >> >> >> >> >> The change for "mask" seems to make it less efficient since it could >> >> >> otherwise be put into a register. >> >> >> >> >> > Totally, this commit spares the 10bytes copy of mcs_mask but adds a less >> >> > efficient indirection to mask. >> >> > I thought of it but kept the symmetry with mcs_mask. >> >> > Apparently you wouldn't mind the dissymmetry so I will re-send using mask >> >> > by value, plus I wrote "updates .." where it is more like "lets the >> >> > ad-hoc masks get overwritten". >> >> It seems to me that all of this could be made more efficient by default >> >> if a mcs mask pointer is only passed to rate control if the user >> >> actually configured a MCS mask. Also, filtering out rates from the mask >> >> that the sta does not support seems a bit unnecessary, since the rate >> >> control usually looks at the HT capabilities and the sta's mcs rx mask >> >> anyway. >> >> >> > Filtering is necessary to lookup alternative downgrade/upgrade rates. >> Right, but the code could be changed to only do the filtering if >> mac80211 needs to look up an alternative downgrade/upgrade rate. >> > With this I agree. > Do you have strong opinions wrt basic rates ? The current code might tx > mc/bc with non-basic rates. The only strong opinion I have about the rate masking code is that it shouldn't waste precious CPU cycles in a hot path ;) - Felix