From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nbd.name ([46.4.11.11]:50650 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751018Ab3GZR7r (ORCPT ); Fri, 26 Jul 2013 13:59:47 -0400 Message-ID: <51F2B90E.2070501@openwrt.org> (sfid-20130726_195950_548860_31E91512) Date: Fri, 26 Jul 2013 19:59:42 +0200 From: Felix Fietkau MIME-Version: 1.0 To: Ben Greear CC: Johannes Berg , linux-wireless@vger.kernel.org Subject: Re: [WT PATCH 4/6] mac80211: Add per-sdata station hash, and sdata hash. References: <1372546738-25827-1-git-send-email-greearb@candelatech.com> <1372546738-25827-4-git-send-email-greearb@candelatech.com> (sfid-20130630_005944_514926_D21D8724) <1373532936.8201.5.camel@jlt4.sipsolutions.net> <51DECF5B.7040002@candelatech.com> <1374828780.8248.24.camel@jlt4.sipsolutions.net> <51F247C1.3090702@openwrt.org> <51F29439.3050607@candelatech.com> <51F297F8.5090608@openwrt.org> <51F29F1C.9000607@candelatech.com> In-Reply-To: <51F29F1C.9000607@candelatech.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2013-07-26 6:09 PM, Ben Greear wrote: > On 07/26/2013 08:38 AM, Felix Fietkau wrote: >> The global hash (with added vif-addr mixing) not only completely fixes >> the many-STA-vif case, also has some other advantages compared to the >> per-sdata hash: >> - Lookup is easier in setups with multiple AP VLANs >> - Better cache footprint (especially important for small embedded devices). >> - You don't need a separate sdata lookup before the sta lookup. >> >> I'm not convinced that keeping separate hashes is cleaner. Especially in >> the AP_VLAN case, ownership is not clear in any way, since there's some >> overlap between multiple sdata entities (belonging to the same BSS). > If someone wants to post such a patch, we can run it through our test > rigs, but I have little time or interest for re-doing the > hashing code again at this time. If your approach does fix the performance > issues we saw, then I'll be more than happy to drop my patch and use > your method. I don't have time to create such a patch myself at this point. I just want to make sure that changes you post don't negatively affect small embedded devices - and this is where the per-sdata hashing could be problematic in my opinion. - Felix