Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753151Ab3FTGFU (ORCPT ); Thu, 20 Jun 2013 02:05:20 -0400 Received: from mail-ea0-f171.google.com ([209.85.215.171]:47478 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751790Ab3FTGFS (ORCPT ); Thu, 20 Jun 2013 02:05:18 -0400 Message-ID: <1371708312.3252.359.camel@edumazet-glaptop> Subject: Re: [net-next rfc 1/3] net: avoid high order memory allocation for queues by using flex array From: Eric Dumazet To: Jason Wang Cc: "Michael S. Tsirkin" , davem@davemloft.net, edumazet@google.com, hkchu@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 19 Jun 2013 23:05:12 -0700 In-Reply-To: <51C28FA7.2070901@redhat.com> References: <1371620452-49349-1-git-send-email-jasowang@redhat.com> <1371620452-49349-2-git-send-email-jasowang@redhat.com> <1371623518.3252.267.camel@edumazet-glaptop> <20130619091132.GA2816@redhat.com> <1371635763.3252.289.camel@edumazet-glaptop> <51C28FA7.2070901@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 677 Lines: 19 On Thu, 2013-06-20 at 13:14 +0800, Jason Wang wrote: > A drawback of NETIF_F_LLTX is that we may contend on qdisc lock > especially when we have a huge number of tx queues. For your information loopback driver is LLTX, and there is no qdisc on it, unless you specifically add one. Once you add a qdisc on a device, you hit the typical contention on a spinlock. But its hard to design a parallel qdisc. So far nobody did that. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/