From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761371AbXGTL1q (ORCPT ); Fri, 20 Jul 2007 07:27:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756314AbXGTL1g (ORCPT ); Fri, 20 Jul 2007 07:27:36 -0400 Received: from wr-out-0506.google.com ([64.233.184.230]:59267 "EHLO wr-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755644AbXGTL1f (ORCPT ); Fri, 20 Jul 2007 07:27:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=qD4ZVMMVRY5d2gwc6pHtH67WJuDbrQMOfnV2VC4NCHCERcKVYNdga42Pk/eKmjNg1hbjAdEgkj7zeIWZyHzAzUKMzpI4D5JZX+96uZV3MUlkYao7F8DKLrN55ZftLPlYVmWYuZPNSgdiwuLPCt8oAIqzPaic/9dXjJ6FXt9gU+s= Message-ID: Date: Fri, 20 Jul 2007 16:57:33 +0530 From: "Satyam Sharma" To: "Chris Snook" Subject: Re: [RFC 1/4] CONFIG_STABLE: Define it Cc: "clameter@sgi.com" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org In-Reply-To: <46A097FE.3000701@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20070531002047.702473071@sgi.com> <20070531003012.302019683@sgi.com> <46A097FE.3000701@redhat.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 7/20/07, Chris Snook wrote: > Satyam Sharma wrote: > > [ Just cleaning up my inbox, and stumbled across this thread ... ] > > > > > > On 5/31/07, clameter@sgi.com wrote: > >> Introduce CONFIG_STABLE to control checks only useful for development. > >> > >> Signed-off-by: Christoph Lameter > >> [...] > >> menu "General setup" > >> > >> +config STABLE > >> + bool "Stable kernel" > >> + help > >> + If the kernel is configured to be a stable kernel then various > >> + checks that are only of interest to kernel development will be > >> + omitted. > >> + > > > > > > "A programmer who uses assertions during testing and turns them off > > during production is like a sailor who wears a life vest while drilling > > on shore and takes it off at sea." > > - Tony Hoare > > > > > > Probably you meant to turn off debug _output_ (and not _checks_) > > with this config option? But we already have CONFIG_FOO_DEBUG_BAR > > for those situations ... > > There are plenty of validation and debugging features in the kernel that go WAY > beyond mere assertions, often imposing significant overhead (particularly when > you scale up) or creating interfaces you'd never use unless you were doing > kernel development work. You really do want these features completely removed > from production kernels. As for entire such "development/debugging-related features", most (all, really) should anyway have their own config options. > The point of this is not to remove one-line WARN_ON and BUG_ON checks (though we > might remove a few from fast paths), but rather to disable big chunks of > debugging code that don't implement anything visible to a production workload. Oh yes, but it's still not clear to me why or how a kernel-wide "CONFIG_STABLE" or "CONFIG_RELEASE" would help ... what's wrong with finer granularity "CONFIG_xxx_DEBUG_xxx" kind of knobs?