From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH] xps-mq: Transmit Packet Steering for multiqueue Date: Wed, 01 Sep 2010 17:54:23 +0200 Message-ID: <1283356463.2556.351.camel@edumazet-laptop> References: <20100823105933.27cd0b80@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Stephen Hemminger , davem@davemloft.net, netdev@vger.kernel.org To: Tom Herbert Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:41143 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751742Ab0IAPy3 (ORCPT ); Wed, 1 Sep 2010 11:54:29 -0400 Received: by wwj40 with SMTP id 40so135719wwj.1 for ; Wed, 01 Sep 2010 08:54:28 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Le mercredi 01 septembre 2010 =C3=A0 08:41 -0700, Tom Herbert a =C3=A9c= rit : > > Why don't we do this in the normal transmit processing. > > There is already so much policy mechanism filters/actions/qdisc tha= t > > doing it in higher level is fighting against these. > > > Are you proposing that TX queue selection be done in the qdiscs? The > queue has to be selected before taking the lock (cannot afford taking > a lock over the whole interface). This would necessitate moving the > locking and probably rearranging a lot of the xmit code around that. Stephen point is not adding yet another layer 'before' qdisc layer. I would like something not as complex as your patch. 1) Why current selection fails ? 2) Could we change current selection to : - Use a lightweight selection, with no special configuration. - Use driver RX multiqueue information if available, in a one-to-one relationship. 3) Eventually have a user selectable selection (socket option, or syste= m wide, but one sysctl, not many bitmasks ;) ).