From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 1 Aug 2001 12:54:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 1 Aug 2001 12:54:29 -0400 Received: from minus.inr.ac.ru ([193.233.7.97]:7178 "HELO ms2.inr.ac.ru") by vger.kernel.org with SMTP id ; Wed, 1 Aug 2001 12:53:52 -0400 Message-Id: <200107312322.DAA00541@mops.inr.ac.ru> Subject: Re: [PATCH] Inbound Connection Control mechanism: Prioritized Accept To: samudrala@us.ibm.COM (Sridhar Samudrala) Date: Wed, 1 Aug 2001 03:22:45 -2000 (MSD) Cc: thiemo@sics.se, dmfreim@us.ibm.COM, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org, lartc@mailman.ds9a.nl, diffserv-general@lists.sourceforge.net, rusty@rustcorp.com.au In-Reply-To: from "Sridhar Samudrala" at Jul 30, 1 00:40:43 am From: Alexey Kuznetsov X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello! > I am not sure how much overhead is involved in maintaining the the no. of > slots left for each priority class. Also what should be the ratio of slots > that need to reserved for each class? It is an experimental value like total size of accept queue, which is also unknown apriori. No differences. > Do you think that the existing PAQ patch with SYN policing is a reasonable > way for prioritizing incoming connection requests? I still did not look at this patch, I have just got some url from netdev. (that blamed by Jamal. :-) Guys, tell your managers they should reserve a bit of money for admins to replace bogus firewalls. ibm site is really not accessible, it is not a joke. :-)). I will look at it tonight. > Preempting existing low priority connections in acceptq with high priority > ones may not be good idea as we need to abort them by sending a RST. Of course. It is _very_ bad idea. :-) Actually, true preemption can be relaized here with moving socket back to SYN-RECV state, converting it to open_request. We just pretend that we did not receive ACK, it is fully legal. But in this case we also have room for effective preemption, stopping process SYN_RECV->ESTABLISHED for low priorities. I.e. exactly, which SYN policing makes. Alexey