Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269776AbUJGKHu (ORCPT ); Thu, 7 Oct 2004 06:07:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267370AbUJGKHt (ORCPT ); Thu, 7 Oct 2004 06:07:49 -0400 Received: from brown.brainfood.com ([146.82.138.61]:38801 "EHLO gradall.private.brainfood.com") by vger.kernel.org with ESMTP id S269777AbUJGKHe (ORCPT ); Thu, 7 Oct 2004 06:07:34 -0400 Date: Thu, 7 Oct 2004 05:07:26 -0500 (CDT) From: Adam Heath X-X-Sender: adam@gradall.private.brainfood.com To: Martijn Sipkema cc: Linux Kernel Mailing List Subject: Re: UDP recvmsg blocks after select(), 2.6 bug? In-Reply-To: <021b01c4ac59$cbe92ea0$161b14ac@boromir> Message-ID: References: <4164CB02.2030607@kegel.com> <20041007080414.GA28999@outpost.ds9a.nl> <021b01c4ac59$cbe92ea0$161b14ac@boromir> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 921 Lines: 21 On Thu, 7 Oct 2004, Martijn Sipkema wrote: > > > It does not matter - this behaviour should not be depended upon. There are > > > lots of other reasons why a packet might in fact not be available, kernels > > > are allowed to drop UDP packets at will. > > > > I've been lurking and reading this thread with great interest. I had been > > leaning towards thinking the kernel was wrong, until I read this email. > > > > This is a very excellent point. > > No, it isn't. If the kernel drops a UDP packet, select() should not return > indicating available data. The kernel can drop a packet after select() returns, and before read() is called. That's the whole point of *U*DP. - 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/