Return-path: Received: from mail-wi0-f170.google.com ([209.85.212.170]:35722 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751189AbaENFOB convert rfc822-to-8bit (ORCPT ); Wed, 14 May 2014 01:14:01 -0400 Received: by mail-wi0-f170.google.com with SMTP id bs8so8114377wib.5 for ; Tue, 13 May 2014 22:14:00 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1399996416.4137.27.camel@jlt4.sipsolutions.net> References: <1397050174-26121-14-git-send-email-michal.kazior@tieto.com> <1398849681-3606-1-git-send-email-michal.kazior@tieto.com> <1399372915.4218.17.camel@jlt4.sipsolutions.net> <1399385141.4218.37.camel@jlt4.sipsolutions.net> <1399450061.5038.10.camel@jlt4.sipsolutions.net> <1399455657.6800.4.camel@dubbel> <1399457760.6800.7.camel@dubbel> <1399460964.10517.12.camel@jlt4.sipsolutions.net> <1399463646.10517.28.camel@jlt4.sipsolutions.net> <1399464536.6800.11.camel@dubbel> <1399464789.10517.29.camel@jlt4.sipsolutions.net> <1399465244.6800.13.camel@dubbel> <1399466312.10517.34.camel@jlt4.sipsolutions.net> <1399467225.10517.35.camel@jlt4.sipsolutions.net> <1399543568.9163.5.camel@jlt4.sipsolutions.net> <1399988536.4137.23.camel@jlt4.sipsolutions.net> <1399996416.4137.27.camel@jlt4.sipsolutions.net> Date: Wed, 14 May 2014 07:14:00 +0200 Message-ID: (sfid-20140514_071407_074884_4630DA29) Subject: Re: [PATCH v5] mac80211: implement multi-vif in-place reservations From: Michal Kazior To: Johannes Berg Cc: Luca Coelho , linux-wireless , Simon Wunderlich Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 13 May 2014 17:53, Johannes Berg wrote: > On Tue, 2014-05-13 at 15:56 +0200, Michal Kazior wrote: > >> > That's pretty much what I'd considered, except that now as far as I read >> > the thread this wasn't sufficient for multi-context, so we'd need lists >> > of old/new contexts? >> >> Hmm.. In what cases do you need a list of old/new contexts? > > That was Luca's scenario, no? Hmm.. I thought of it more as a theoretical appliance of the transaction API. Let me re-post his example: > With the generic transactions you could do: > - new chanctx2 > - new chanctx3 > - switch vif1 chanctx1->chanctx2 > - switch vif2 chanctx1->chanctx3 > - del chanctx1 >From this I infer you can run at least 2 chanctx since that's what you end up with. This means you can perform one of the switches separately because only 1 chanctx was used (that's the easy part that never really required transactions or multi-vif-chanctx-assign to begin with). The other switch would fall into the "incompat case" where you need to basically swap chanctx for one of the vifs in the example. So I fail to see why we would need to have a list of old/new contexts in the proposed switch_vif_chanctx(), at least for now. Michał