Return-path: Received: from mail-we0-f175.google.com ([74.125.82.175]:61876 "EHLO mail-we0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753228Ab3CJXFI (ORCPT ); Sun, 10 Mar 2013 19:05:08 -0400 Received: by mail-we0-f175.google.com with SMTP id x8so2925552wey.6 for ; Sun, 10 Mar 2013 16:05:07 -0700 (PDT) Date: Mon, 11 Mar 2013 00:06:00 +0100 From: Karl Beldan To: Felix Fietkau 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 Message-ID: <20130310230600.GC3824@gobelin> (sfid-20130311_000514_279998_F151A56C) 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <513D08B5.1030007@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: 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. Karl