From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752581AbaBRVdz (ORCPT ); Tue, 18 Feb 2014 16:33:55 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:43941 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751687AbaBRVdy (ORCPT ); Tue, 18 Feb 2014 16:33:54 -0500 Date: Tue, 18 Feb 2014 13:33:44 -0800 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, oleg@redhat.com, sbw@mit.edu, linux@horizon.com Subject: Re: [PATCH tip/core/rcu 15/55] rcutorture: Abstract rcu_torture_random() Message-ID: <20140218213344.GY4250@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20140217221231.GA8419@linux.vnet.ibm.com> <1392675179-11560-1-git-send-email-paulmck@linux.vnet.ibm.com> <1392675179-11560-15-git-send-email-paulmck@linux.vnet.ibm.com> <20140218001137.GC19929@thin> <20140218002248.GU4250@linux.vnet.ibm.com> <20140218002743.GF19929@thin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140218002743.GF19929@thin> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14021821-8236-0000-0000-0000075D3B44 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 17, 2014 at 04:27:44PM -0800, Josh Triplett wrote: > On Mon, Feb 17, 2014 at 04:22:48PM -0800, Paul E. McKenney wrote: > > On Mon, Feb 17, 2014 at 04:11:37PM -0800, Josh Triplett wrote: > > > On Mon, Feb 17, 2014 at 02:12:19PM -0800, Paul E. McKenney wrote: > > > > From: "Paul E. McKenney" > > > > > > > > Because rcu_torture_random() will be used by the locking equivalent to > > > > rcutorture, pull it out into its own module. > > > > > > > > Suggested-by: Rusty Russell > > > > Signed-off-by: Paul E. McKenney > > > > > > I'd suggest making CONFIG_TORTURE_TEST a completely invisible option, > > > with no description; it should only be brought in via "select". > > > > > > Also, it doesn't need most of the headers it currently includes. > > > > > > Have you considered moving it into the existing random generation > > > infrastructure, as something like "fast_insecure_nonblocking_random"? > > > That seems more generally useful. > > > > George Spelvin was also advising me on random-number generation in > > rcutorture, so I added him on CC. In any case, I would not be adverse > > to using some other random-number service, as long as it is fast enough. > > (George suggested some optimizations that I have not yet tried out.) > > I suspect the fastest way to find out about any existing generator with > the desired properties would be to post this one as a patch to the > random number infrastructure and read the resulting replies. :) ;-) Random-number improvements on todo list. Thanx, Paul