Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262603AbVDGVOX (ORCPT ); Thu, 7 Apr 2005 17:14:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262604AbVDGVOX (ORCPT ); Thu, 7 Apr 2005 17:14:23 -0400 Received: from waste.org ([216.27.176.166]:27302 "EHLO waste.org") by vger.kernel.org with ESMTP id S262603AbVDGVOS (ORCPT ); Thu, 7 Apr 2005 17:14:18 -0400 Date: Thu, 7 Apr 2005 14:12:57 -0700 From: Matt Mackall To: Simon Derr Cc: Yura Pakhuchiy , Patrice Martinez , linux-kernel@vger.kernel.org Subject: Re: /dev/random problem on 2.6.12-rc1 Message-ID: <20050407211257.GK25554@waste.org> References: <42552A33.6070704@ext.bull.net> <1112879666.2035.10.camel@chaos.void> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1760 Lines: 45 On Thu, Apr 07, 2005 at 05:36:59PM +0200, Simon Derr wrote: > > > On Thu, 7 Apr 2005, Yura Pakhuchiy wrote: > > > On Thu, 2005-04-07 at 14:40 +0200, Patrice Martinez wrote: > > > When using a machine with a 2612-rc 1kernel, I encounter problems > > > reading /dev/random: > > > it simply nevers returns anything, and the process is blocked in the > > > read... > > > The easiest way to see it is to type: > > > od < /dev/random > > > > > > Any idea? > > > > Because, /dev/random use user input, mouse movements and other things to > > generate next random number. Use /dev/urandom if you want version that > > will never block your machine. > > > > Read "man 4 random" for details. > > > Something changed since previous versions of the kernel, I guess. > Running `find /usr | wc' on a ssh session generates both network and disk > activity, and you should not expect any other kind of input on a networked > server. FYI, network activity only generates entropy on a very small subset of NICs, and probably not the one you're using. This is good, as network activity is assumed passively observable/timable. > Anyway, still zero bytes coming from /dev/random, for the few minutes I > waited. Are you and Patrice both experiencing this on the same machine? What was the last kernel that was known to work for you? Do you see the contents of /proc/sys/kernel/random/entropy_avail change over time? Are there any other entropy consumers on your machine? -- Mathematics is the supreme nostalgia of our time. - 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/