Return-path: Received: from mail.candelatech.com ([208.74.158.172]:44927 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754054Ab3EaSvw (ORCPT ); Fri, 31 May 2013 14:51:52 -0400 Message-ID: <51A8F141.5050804@candelatech.com> (sfid-20130531_205156_577264_2AB9AD65) Date: Fri, 31 May 2013 11:51:45 -0700 From: Ben Greear MIME-Version: 1.0 To: Johannes Berg CC: Felix Fietkau , "linux-wireless@vger.kernel.org" , netdev Subject: Re: Another try at getting pktgen to work with wifi. References: <51A79E4A.7000609@candelatech.com> <51A7B049.9090201@openwrt.org> <51A7BA63.4080403@candelatech.com> <51A857BF.7070008@openwrt.org> <51A8DC1C.1040908@candelatech.com> (sfid-20130531_192143_291284_FB196B0A) <1370021846.14117.13.camel@jlt4.sipsolutions.net> <51A8E53E.8030101@candelatech.com> <1370025698.14117.15.camel@jlt4.sipsolutions.net> In-Reply-To: <1370025698.14117.15.camel@jlt4.sipsolutions.net> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 05/31/2013 11:41 AM, Johannes Berg wrote: > On Fri, 2013-05-31 at 11:00 -0700, Ben Greear wrote: > >> I think it might be more that the wifi stacks have some specific >> assumptions about how skb->priority maps to queues and QoS. If >> they get out of sync, then the TID mappings and so forth get >> confused. > > What I'm saying though is that I don't see where skb->priority is even > _used_ in the wifi stack. I can see it getting set, but not used. ieee80211_downgrade_queue wme_downgrade_ac // sort of ieee80211_select_queue_80211 // sort of...seems twiddling skb->priority is more of a by-product here. cfg80211_classify8021d >>> Actually that makes it seem like something else should be doing packet >>> classification, not mac80211 in select_queue()? >>> >>> Where is skb->priority actually really used in mac80211? I don't see >>> much? >> >> There's a bit more in net/wireless/util.c, at least (cfg80211_classify8021d, for instance). > > But that's pretty much all assignments. cfg80211_classify8021d uses it to determine the queue in if skb->priority is set to a special range (hard coded un-documented hack from hell, it appears). I didn't go looking to find out where those magic values might be set. >> The mac80211/wme.c uses it. Some of this is called from the drivers >> (line 1916 or so of ath9k/xmit.c). > > What's called there? I don't see any reason for that to use > skb->priority? Ok, I was confused about that..but that *is* the code that pukes if you have have mis-matched queues like you get with pktgen in upstream kernels... Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com