Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932637AbWHMAqf (ORCPT ); Sat, 12 Aug 2006 20:46:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932631AbWHMAqe (ORCPT ); Sat, 12 Aug 2006 20:46:34 -0400 Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:22429 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S932633AbWHMAqc (ORCPT ); Sat, 12 Aug 2006 20:46:32 -0400 Date: Sat, 12 Aug 2006 17:46:51 -0700 (PDT) Message-Id: <20060812.174651.113732891.davem@davemloft.net> To: a.p.zijlstra@chello.nl Cc: johnpol@2ka.mipt.ru, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, phillips@google.com Subject: Re: [RFC][PATCH 0/9] Network receive deadlock prevention for NBD From: David Miller In-Reply-To: <1155377887.13508.27.camel@lappy> References: <1155374390.13508.15.camel@lappy> <20060812093706.GA13554@2ka.mipt.ru> <1155377887.13508.27.camel@lappy> X-Mailer: Mew version 4.2 on Emacs 21.4 / 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: 679 Lines: 17 From: Peter Zijlstra Date: Sat, 12 Aug 2006 12:18:07 +0200 > 65535 sockets * 128 packets * 16384 bytes/packet = > 1^16 * 1^7 * 1^14 = 1^(16+7+14) = 1^37 = 128G of memory per IP > > And systems with a lot of IP numbers are not unthinkable. TCP restricts the amount of global memory that may be consumed by all TCP sockets via the tcp_mem[] sysctl. Otherwise several forms of DoS attacks would be possible. - 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/