From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Sutter Subject: Re: [net-next PATCH 1/3] net: make default tx_queue_len configurable Date: Wed, 29 Jul 2015 23:34:28 +0200 Message-ID: <20150729213428.GC15554@orbit.nwl.cc> References: <1438203103-27013-1-git-send-email-phil@nwl.cc> <1438203103-27013-2-git-send-email-phil@nwl.cc> <20150729210618.GF32705@breakpoint.cc> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, Jesper Dangaard Brouer , Cong Wang , Eric Dumazet , David Miller To: Florian Westphal Return-path: Received: from orbit.nwl.cc ([176.31.251.142]:37022 "EHLO mail.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753958AbbG2Vec (ORCPT ); Wed, 29 Jul 2015 17:34:32 -0400 Content-Disposition: inline In-Reply-To: <20150729210618.GF32705@breakpoint.cc> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Jul 29, 2015 at 11:06:18PM +0200, Florian Westphal wrote: > Phil Sutter wrote: [...] > > +config DEFAULT_TX_QUEUE_LEN > > + prompt "Default TX queue length (in packets)" if EXPERT > > + int > > + default 1000 # Ethernet wants good queues > > + help > > + Set the default value of tx_queue_len for newly created network > > + interfaces. It is used by queueing disciplines to determine how many > > + packets to keep in backlog before starting to drop new ones. > > + > > + The default value of 1000 packets is there for a very long time and > > + in combination with GSO way too big. > > + > > I can't see how this could be used in a meaningful way. > > No distro is going to touch this. > > I don't think sysctl value would help either. I just didn't want to introduce yet another magic value assignment. It's merely a #define with a little flexibility and a subtle note that the default should be changed attached. Cheers, Phil