From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Abeni Subject: [PATCH RFC 0/2] tun: lockless xmit Date: Wed, 13 Apr 2016 11:04:45 +0200 Message-ID: Cc: "David S. Miller" , "Michael S. Tsirkin" , Hannes Frederic Sowa , "Eric W. Biederman" , Greg Kurz , Jason Wang To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:51678 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759637AbcDMJFK (ORCPT ); Wed, 13 Apr 2016 05:05:10 -0400 Sender: netdev-owner@vger.kernel.org List-ID: This patch series try to remove the need for any lock in the tun device xmit path, significantly improving the forwarding performance when multiple processes are accessing the tun device (i.e. in a nic->bridge->tun->vm scenario). The lockless xmit is obtained explicitly setting the NETIF_F_LLTX feature bit and removing the default qdisc. Unlikely most virtual devices, the tun driver has featured a default qdisc for a long period, but it already lost such feature in linux 4.3. Paolo Abeni (2): tun: don't require serialization lock on tx tun: don't set a default qdisc drivers/net/tun.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) -- 1.8.3.1