Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Feb 2003 04:49:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Feb 2003 04:49:09 -0500 Received: from pizda.ninka.net ([216.101.162.242]:32207 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Fri, 21 Feb 2003 04:49:07 -0500 Date: Fri, 21 Feb 2003 01:43:16 -0800 (PST) Message-Id: <20030221.014316.69598293.davem@redhat.com> To: ak@suse.de Cc: sim@netnation.com, linux-kernel@vger.kernel.org, linux-net@vger.kernel.org Subject: Re: Longstanding networking / SMP issue? (duplextest) From: "David S. Miller" In-Reply-To: <20030221072719.GD25144@wotan.suse.de> References: <20030220093422.GA16369@wotan.suse.de> <20030220.202438.10564686.davem@redhat.com> <20030221072719.GD25144@wotan.suse.de> X-FalunGong: Information control. X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1129 Lines: 27 From: Andi Kleen Date: Fri, 21 Feb 2003 08:27:19 +0100 For icmp_xmit_lock it can be only done in a limited fashion - you are always restricted by the buffer size of the ICMP socket. Also I don't know how to lock the socket from BH context nicely - the only simple way probably is the trick from the retransmit timer to just try again in a jiffie, but could have nasty queueing up under high load. Fixing the error drop behaviour of TCP will be somewhat nasty too. In both cases you'll need a retry timer (unreliable) or an dedicated ICMP backlog (complicated) The big problem is that we have one ICMP socket for UP and only one for SMP too. That's just dumb, we should make this be a per-cpu thing. I suspect this will fix the original bug report. I don't think the TCP case is much of an issue. TCP retries things etc. - 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/