From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: softirqs are invoked while bottom halves are masked Date: Wed, 13 Jul 2011 09:38:53 +0200 Message-ID: <1310542733.2634.17.camel@edumazet-laptop> References: <1310465411.3314.6.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <20110712.050817.1253941735409335652.davem@davemloft.net> <20110712.051316.1963034055315982365.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: David Miller , ronny.meeus@gmail.com, linuxppc-dev@ozlabs.org, netdev@vger.kernel.org, afleming@freescale.com To: Thomas De Schampheleire Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:41125 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965002Ab1GMHi7 (ORCPT ); Wed, 13 Jul 2011 03:38:59 -0400 Received: by wwe5 with SMTP id 5so5700274wwe.1 for ; Wed, 13 Jul 2011 00:38:58 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Le mercredi 13 juillet 2011 =C3=A0 09:20 +0200, Thomas De Schampheleire= a =C3=A9crit : > I just want to mention that, although you seem to think that we > shouldn't have created this thread in the first place, your and Eric'= s > remarks have actually helped us in identifying the problem and > increasing our understanding. >=20 Thread was fine IMHO, but should have mentioned the context of "non standard linux-2.6 or net-next-2.6 trees" I would like to mention NETIF_F_LLTX existence. While being marked deprecated, it allows a lockless tx path : The device transmit handler can then perform custom actions, including its own locking if needed. If the user wants a specific Qdisc setup (instead of a no qdisc one), i= t still can. veth, loopback, dummy, macvlan & bond devices use NETIF_F_LLTX for example. But ndo_start_xmit() must always be called with BH disabled.