From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wr-out-0506.google.com with SMTP id 67so638363wri for ; Fri, 20 Jul 2007 04:27:34 -0700 (PDT) Message-ID: Date: Fri, 20 Jul 2007 16:57:33 +0530 From: "Satyam Sharma" Subject: Re: [RFC 1/4] CONFIG_STABLE: Define it 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: owner-linux-mm@kvack.org Return-Path: To: Chris Snook Cc: "clameter@sgi.com" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org List-ID: 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? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org