From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:42350 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753853AbYGOJhE (ORCPT ); Tue, 15 Jul 2008 05:37:04 -0400 Subject: Re: TXQ real_num_tx_queues comments/questions From: Johannes Berg To: David Miller Cc: netdev@vger.kernel.org, linux-wireless@vger.kernel.org In-Reply-To: <20080715.022854.55875400.davem@davemloft.net> References: <1215769627.3483.107.camel@johannes.berg> <20080715.021637.103260952.davem@davemloft.net> <1216113923.3535.14.camel@johannes.berg> <20080715.022854.55875400.davem@davemloft.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-JrPZzy9lLpE7gY2+S9VF" Date: Tue, 15 Jul 2008 11:37:01 +0200 Message-Id: <1216114621.3535.18.camel@johannes.berg> (sfid-20080715_113714_231774_BE0DAD17) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-JrPZzy9lLpE7gY2+S9VF Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2008-07-15 at 02:28 -0700, David Miller wrote: > From: Johannes Berg > Date: Tue, 15 Jul 2008 11:25:23 +0200 >=20 > > > It seems to me that a simple synchronize_net() call near the end of > > > agg queue removal would solve your problem as-is, wouldn't it? > >=20 > > Well, as far as I can tell we can't do that there because it's in > > tasklet context/called under spinlocks so it has to be atomic. I think. >=20 > Right, my bad. Also, I don't actually think it is sufficient since select_queue isn't called under rcu lock, so even if we synchronize_net() somewhere there we can still end up not having waited long enough, no? > It seems that there can end up being holes in the queue > space on mac80211, which slightly complicates matters. Yes, but why does it complicate matters? From mac80211's POV it's just that select_queue must have known about the removed queue when the requeue is done. And we can defer the requeue to a workqueue. johannes --=-JrPZzy9lLpE7gY2+S9VF Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJIfG+5AAoJEKVg1VMiehFYPVIP/RFO0w0Xw5RYsbOgOHyEHAHP I/iJ3oi1vQdOvTK2aymo/ZiDjRAEWpveWpioPbhdwg7XJGddXncgSA3vXPcOSHR3 VaCad0DTM0IdimQGSUbs3j28hWThiTEbbUJVV36QGo99q+dup9yTPSYTX/607Pt9 2ktND/pRkLhyCk/i8KBRm7aE/Vsbh8rT7H7NcDiJDAr+6e3M7mtPajE1V+Flz7mF p6ww6pLWNr/wG31kS92ZB510aI/+0OjwraSWceYXq5Q8SajL18XtS7A04UxmfnDo YsDjmxkrynBFAmCDGBc18NKgNL16T9HP/EEHeiMpWVfKmTNo879BqsHBPn9iY2Sk KiwHxGwyYN78buCqEFvK7XxKWL7SHJRwF+fHZ4zbEvl6JblPMK5mY0nJTdXhX1PM hGCQRkL21j5ANoT8p7JnyKxuRJrCP6QSv3c/P8zrEWqBPQhaHVKjRHFUWb5WAC7l BRnOjYFoVfecjF0UH6jK9yFPuRY9CH5I2btVEtGRxuB900AhOgdVuDYLRJMDwagA zwO6s9dbz0AWVeCkS5Gdh56X7Wq9zKqSwJIRjxauJg4cg4VotFINstIRMp81LRsk kvE2WacuKcDbwnq00QFoYNzM5hj12AeXeJLWCCaWC4s2EWnKTAbiWuG/aPBhqJ4u KybqWJQqgNzQzk+WAQr7 =AZe8 -----END PGP SIGNATURE----- --=-JrPZzy9lLpE7gY2+S9VF--