From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754432Ab1EQMUb (ORCPT ); Tue, 17 May 2011 08:20:31 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:64457 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754316Ab1EQMU2 (ORCPT ); Tue, 17 May 2011 08:20:28 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=L8vD4Yd8zXk2n6Q+yG9qsFoF1eH+NDmZlXf+pRLQRN/P3vm9qwFJR0g2UPVKUUXBax tExn4zo6nhyGi72S66Y1WNiL0GHc6+NrvOTS8uyW6kpaHfVhaLJr8UGft+6EW6nh+a+t 2R+47f2aUQ0lNa6u0Rf/DICQSPoZYGnW32tt4= Subject: Re: [PATCH] tcp: Expose the initial RTO via a new sysctl. From: Eric Dumazet To: Hagen Paul Pfeifer Cc: Benoit Sigoure , davem@davemloft.net, kuznet@ms2.inr.ac.ru, pekkas@netcore.fi, jmorris@namei.org, yoshfuji@linux-ipv6.org, kaber@trash.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: <1305618020-72535-1-git-send-email-tsunanet@gmail.com> <1305618020-72535-2-git-send-email-tsunanet@gmail.com> <1305619677.2850.11.camel@edumazet-laptop> Content-Type: text/plain; charset="UTF-8" Date: Tue, 17 May 2011 14:20:23 +0200 Message-ID: <1305634823.2850.90.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le mardi 17 mai 2011 à 13:02 +0200, Hagen Paul Pfeifer a écrit : > On Tue, 17 May 2011 10:07:57 +0200, Eric Dumazet wrote: > > > I wont discuss if introducing a new sysctl is welcomed, only on patch > > issues. I believe some work in IETF is done to reduce the 3sec value to > > 1sec anyway. > > Why not? Just because I let this point to David and others. I personally dont care that much. > I though all new knobs in this area should be done on a per route > metric so it can be controlled on a per path basis. RTO should be > adjustable on a per path basis, because it depends on the path. > Adding many knobs to each clone had a huge cost on previous kernels. (Think some machines have millions entries in IP route cache), this used quite a lot of memory. With latest David work, we'll consume less ram, because we can now share settings, instead of copying them on each dst entry. > Some months back [1] I posted a patch to enable/disable TCP quick ack > mode, which has nothing to do with network paths, just with a local server > policy. But David rejected the patch with the argument that I should use a > per path knob (this is a little bit inapprehensible for me, but David has > the last word). Well, if nobody speaks after David, he has the last word indeed. BTW, I remember Stephen actually asked the per route thing, not David. http://kerneltrap.org/mailarchive/linux-netdev/2010/8/23/6283641 Then David also stated it : http://kerneltrap.org/mailarchive/linux-netdev/2010/8/23/6283678 If you really want tcp_quickack thing you really should do it as requested by both Stephen & David ;) Unfortunately, I dont know if its really needed or worthwhile.