Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:37927 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757608AbZC1VSA (ORCPT ); Sat, 28 Mar 2009 17:18:00 -0400 Subject: Re: [PATCH 7/8] mac80211: fix aggregation to not require queue stop From: Johannes Berg To: "Luis R. Rodriguez" Cc: "Luis R. Rodriguez" , John Linville , linux-wireless@vger.kernel.org, Hauke Mehrtens In-Reply-To: <43e72e890903281406w528719b1vda8128255f1ac707@mail.gmail.com> (sfid-20090328_220623_318840_66621554) References: <20090323162834.154525349@sipsolutions.net> <20090323163053.344441542@sipsolutions.net> <20090328045529.GF5543@bombadil.infradead.org> <1238262118.4217.13.camel@johannes.local> <43e72e890903281218s6b4eeb9eu4a97aa3e87c5a3a6@mail.gmail.com> <1238269957.4217.24.camel@johannes.local> <43e72e890903281326j1bba2456j3b82bf3831b614f6@mail.gmail.com> <1238272957.4217.28.camel@johannes.local> <43e72e890903281406w528719b1vda8128255f1ac707@mail.gmail.com> (sfid-20090328_220623_318840_66621554) Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-w1xIWzJ0EX5VpdYpdLSl" Date: Sat, 28 Mar 2009 22:17:48 +0100 Message-Id: <1238275068.4217.31.camel@johannes.local> (sfid-20090328_221806_733581_44717399) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-w1xIWzJ0EX5VpdYpdLSl Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Sat, 2009-03-28 at 14:06 -0700, Luis R. Rodriguez wrote: > My point was that if you have the tasklet handled by a separate CPU > the DRV flag would most likely be set by the time the addba response > comes back. On a UP box though you have no option but to wait for wait > for it to be done after we send off the addba request so then it is a > race between the scheduler to schedule the tasklet and the remote > station's speed + the IRQ processing of the received response. Ah, I see what you mean. But this goes off the same tasklet :) so ath9k doesn't have a problem in any case. > If we would somehow be able to ensure pending BHs complete before we > process the addba response this wouldn't be needed in both places. No, we can't ensure that -- the driver might very well take longer and we don't have a way to only process the received frame later. > Anyway I'm also stating that its likely that the ampdu start action is > slower with iwlagn as interaction with the firmware is required so I > would suspect one can see this behavior more likely on UP iwlagn > boxen. >=20 > Where did you see it? I didn't actually see it :) But iwlagn can possibly flush the queue before calling back to the cb. johannes --=-w1xIWzJ0EX5VpdYpdLSl Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJJzpP5AAoJEKVg1VMiehFYr/0QAKV1XczsTVvMhjFHrL9Vd2JB Cl7dz8VK102Wuvg8SFhDoxGyLVTN6bLWN7IJhETh3poZ7M6WqPZd+mbh9ki5ZR6l A1Pse8g3xHfYBNzulkvXXfUhUCv+6J0UZ32lA/Vo2hmahaqFPERu6q7ax1NS5mTb /lUY/2GMVIyhVgk0ABCqmPbC7lDGLvlEmJno1wFkm3TcF8j1tuJQ7N1mZVHx4wlL DOmh9KZb6+unIzVdFP4NNj6q56vU7GDGoBN2hMBBbF847kK0cLwjaT/jBZWjcK/L zmeARiB7Aqz2COpy8Xg0NX+sgokaiP7FkeRQPGNJTJjFBA6oxFXKgS/MkUwvHEB8 eRxJEERRn9bDZn6dInXPGIVJ60RPkRkEQIVesP5ndxyb/Ix2cIHWdu224QoyEYsY bD3hNZHFkGaS7tCd99gt/n4gVyIvJxwV6yU5vyL1LnppTH2zUdLxjatUloXo37YT 54DtEXxAp0DLNbZ54QBdckJLIGYcZqbeGLLBT8n8PgH9vs+51DchE/krXxALfukH lTdYlaWV36amJqQ+ibD79QvLcz8qOK03w7/THPgZut1+fIZjJaQHeN97WR0eAPQV a6OMKag+/wPl6m5ef5xAar1gxUTo/Vh+nHnFepuSqlQ4DFn3ZkBpCrVA3SAbzkPz 1MTzd8VcJNQFPn4MBqmA =346D -----END PGP SIGNATURE----- --=-w1xIWzJ0EX5VpdYpdLSl--