Date: Sat, 22 Mar 2014 12:16:30 -0600 From: Warner Losh <imp@bsdimp.com> To: John-Mark Gurney <jmg@funkthat.com> Cc: src-committers@FreeBSD.org, Ian Lepore <ian@FreeBSD.org>, svn-src-all@FreeBSD.org, Andrew Turner <andrew@fubar.geek.nz>, svn-src-head@FreeBSD.org, Ruslan Bukin <br@FreeBSD.org> Subject: Re: svn commit: r263424 - head/sys/arm/conf Message-ID: <F3F67C3A-8C27-4FE2-ABF5-91438701A193@gmail.com> In-Reply-To: <20140322180151.GY32089@funkthat.com> References: <201403201701.s2KH1L84024044@svn.freebsd.org> <20140321094316.76ccf459@bender.Home> <1395412070.81853.8.camel@revolution.hippie.lan> <20140321190402.GT32089@funkthat.com> <1395494755.81853.38.camel@revolution.hippie.lan> <20140322180151.GY32089@funkthat.com>
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On Mar 22, 2014, at 12:01 PM, John-Mark Gurney <jmg@funkthat.com> wrote: > Ian Lepore wrote this message on Sat, Mar 22, 2014 at 07:25 -0600: >> On Fri, 2014-03-21 at 12:04 -0700, John-Mark Gurney wrote: >>> Ian Lepore wrote this message on Fri, Mar 21, 2014 at 08:27 -0600: >>>> On Fri, 2014-03-21 at 09:43 +0000, Andrew Turner wrote: >>>>> On Thu, 20 Mar 2014 17:01:21 +0000 (UTC) >>>>> Ruslan Bukin <br@FreeBSD.org> wrote: >>>>>=20 >>>>>> Author: br >>>>>> Date: Thu Mar 20 17:01:21 2014 >>>>>> New Revision: 263424 >>>>>> URL: http://svnweb.freebsd.org/changeset/base/263424 >>>>>>=20 >>>>>> Log: >>>>>> Disable debugging by default. >>>>>=20 >>>>> I don't like this on head. I have found a number of issues that = were >>>>> hidden because the kernel config most people were using for = development >>>>> had WITNESS, INVARIANTS and DIAGNOSTIC disabled. >>>=20 >>> I agree... HEAD needs these to make sure they are production = ready... >>>=20 >>>> I disagree. Witness is essentially useless anymore, because there = are >>>> so many known LORs that nobody cares about when you report them = that all >>>> it does is spews noise. Maybe it's useful when you're looking for = a >>>> particular problem, but leaving it on all the time has just lost = its >>>> value. >>>=20 >>> I wouldn't be tracking down an AVILA bug if it wasn't for = INVARIANTS.. >>>=20 >>> Also, your complaint is solely about WITNESS not the other ones... >>>=20 >>> Considering how many people are writing new drivers for ARM, and = might >>> be introducing locking issues w/ those new drivers, WITNESS should = be >>> included, plus, if you disable INVARIANTS, it means that all the >>> lock assert functions will be turned off, and we might miss an odd >>> calling stack which doesn't hold a lock or something... >>>=20 >>> If you're using HEAD for performance, it's easy to turn these off.. >>>=20 >>=20 >> My complaint is only about witness. >=20 > echo debug.witness.watch=3D0 >> /etc/sysctl.conf >=20 > :) Not as fast as completely turning it off, but almost there.. >=20 >> But... about being easy to turn off... how do they get turned off on >> non-head branches? Does re@ really have to go grovel through 77 = config >> files turning off diagnostic options? Do we have to handle that >> difference when merging things to stable branches? >=20 > Apparently they do: > https://svnweb.freebsd.org/base?view=3Drevision&revision=3D256283 >=20 > Though, handling merging is an issue for all arches... possibly more > anoying for ARM since it's so actively developed... >=20 >> Last time I tried to put something into arm/conf/DEFAULTS I got my = hand >> slapped, but... putting the diagnostic options in there on head and = not >> on stable branches would make the "touch 77 config files" problem go >> away. >=20 > Yes, I agree this is a problem and needs a solution, and I do agree > DEFAULTS would be a resonable place, but since there are others that > feel more strongly about what goes in DEFAULTS, they should speak = about > it.. DEFAULTS is only for mandatory options. WITNESS isn=92t a mandatory = option so it doesn=92t belong there. That was the agreement when we created = DEFAULTS and if we want to have another file that=92s always included, we should = go the std.all route. Or better yet, switch to a system that=92s not so creaky = and cranky that we can more easily expand... Warner=
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