Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266648AbUJGOwp (ORCPT ); Thu, 7 Oct 2004 10:52:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264085AbUJGOwp (ORCPT ); Thu, 7 Oct 2004 10:52:45 -0400 Received: from clock-tower.bc.nu ([81.2.110.250]:58030 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S266648AbUJGOvk (ORCPT ); Thu, 7 Oct 2004 10:51:40 -0400 Subject: Re: UDP recvmsg blocks after select(), 2.6 bug? From: Alan Cox To: Martijn Sipkema Cc: Paul Jakma , Chris Friesen , "Richard B. Johnson" , "David S. Miller" , joris@eljakim.nl, Linux Kernel Mailing List In-Reply-To: <001c01c4ac76$fb9fd190$161b14ac@boromir> References: <20041006080104.76f862e6.davem@davemloft.net> <20041006082145.7b765385.davem@davemloft.net> <4164EBF1.3000802@nortelnetworks.com> <001601c4ac72$19932760$161b14ac@boromir> <001c01c4ac76$fb9fd190$161b14ac@boromir> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1097156929.31753.47.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Thu, 07 Oct 2004 14:48:53 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 882 Lines: 18 On Iau, 2004-10-07 at 15:07, Martijn Sipkema wrote: > > Much can change between the select() and recvmsg - things outside of > > kernel control too, and it's long been known. > > There is no change; the current implementation just checks the validity of > the data in the recvmsg() call and not during select(). The accept one is documented by Stevens and well known. In the UDP case currently we could get precise behaviour - by halving performance of UDP applications like video streaming. We probably don't want to because we can respond intelligently to OOM situations by freeing the queue if we don't enforce such a silly rule. - 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/