From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 20 Jan 2004 23:27:00 +0100 From: Adrian Bunk Subject: Re: 2.6.1-mm5 (compile stats) Message-ID: <20040120222700.GJ12027@fs.tum.de> References: <20040120000535.7fb8e683.akpm@osdl.org> <1074614919.31724.0.camel@cherrypit.pdx.osdl.net> <20040120215705.GG12027@fs.tum.de> <1074636910.16765.14.camel@cherrytest.pdx.osdl.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1074636910.16765.14.camel@cherrytest.pdx.osdl.net> Sender: owner-linux-mm@kvack.org Return-Path: To: John Cherry Cc: Andrew Morton , "linux-kernel@vger.kernel.org" , linux-mm@kvack.org List-ID: On Tue, Jan 20, 2004 at 02:15:10PM -0800, John Cherry wrote: >... > > Regarding allnoconfig: > > allnoconfig is a completely pathological case. It says "n" to support > > for ISA, MCA and PCI, and neither networking nor any block devices. > > Besides, it says "n" to ELF, a.out and other binary formats. > > Demanding that allnoconfig should compile (although the resulting kernel > > is completely useless) sounds a bit like demanding that no change in the > > kernel is allowed to cause regressions in the dbench results... > > It is useful to omit a common option like e.g. PCI and check whether the > > kernel still compiles, but allnoconfig removes nearly everything and > > compiles such a small part of the kernel, that it's hardly useful. > > I realize that allnoconfig is pathological, but it has caught several > config errors. One would never try to boot from such a config. Builds > based on allnoconfig have one purpose and that purpose is to validate > that defines are not used in cases where they are NOT defined in the > configuration. Developers will quite often code a feature or > architecture with the config parameters always ON. When the config > option is turned OFF, I will find compile errors, undefined variables, > and the like. This is actually quite a valuable screen. The problem is that allnoconfig turns _everything_ off. Cases like e.g. CONFIG_PROC_FS=n are interesting, but allnoconfig doesn't really test them since allnoconfig also says "n" to all drivers. > If developers feel that this has outlived its usefulness, I'll remove it > from the compile regressions. However, all I have received at this > point have been requests to put an allnoconfig build into the > regressions. I'd like to hear from the people requesting it why they consider it useful. In my personal experience, compiling allyesconfig but with CONFIG_SMP=n (which enables BROKEN_ON_SMP drivers), and compiling with gcc 2.95 are more interesing (and more realistic) configurations than allnoconfig that find many compile errors. > John cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed -- 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: aart@kvack.org