From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net ([184.105.139.130]:35308 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751232AbeCLTEI (ORCPT ); Mon, 12 Mar 2018 15:04:08 -0400 Date: Mon, 12 Mar 2018 15:04:06 -0400 (EDT) Message-Id: <20180312.150406.1432667769589045118.davem@davemloft.net> To: stephen@networkplumber.org Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org Subject: Re: de-indirect TCP congestion control From: David Miller In-Reply-To: <20180312114552.3f51e6ac@xeon-e3> References: <20180312114552.3f51e6ac@xeon-e3> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org List-ID: From: Stephen Hemminger Date: Mon, 12 Mar 2018 11:45:52 -0700 > Since indirect calls are expensive, and now even more so, perhaps we should figure out > a way to make the default TCP congestion control hooks into direct calls. > 99% of the users just use the single CC module compiled into the kernel. Who is this magic user with only one CC algorithm enabled in their kernel? I want to know who this dude is? I don't think it's going to help much since people will have I think at least two algorithms compiled into nearly everyone's tree. Distributions will enable everything. Google is going to have at least two algorithms enabled. etc. etc. etc. Getting rid of indirect calls is a fine goal, but the precondition you are mentioning to achieve this doesn't seem practical at all.