Messages in this thread | | | Date | Tue, 15 Apr 2014 08:24:52 -0700 | From | Greg KH <> | Subject | Re: Hardware dependencies in Kconfig |
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On Tue, Apr 15, 2014 at 07:50:05AM -0400, Josh Boyer wrote: > On Tue, Apr 15, 2014 at 12:52 AM, Greg KH <gregkh@linuxfoundation.org> wrote: > > On Mon, Apr 14, 2014 at 11:12:54PM +0200, Jean Delvare wrote: > >> And it's not going to get any better over time. As others have already > >> mentioned, most new drivers these days are NOT for x86, they are for > >> ARM, AVR32 and other fancy embedded architectures. > >> > >> "Just say m to everything" is just so wrong today that at SUSE we are > >> very close to switching our policy to "just say no to everything and > >> wait for people to complain about missing drivers." This may not sound > >> too appealing but this is the only way to keep the kernel package at a > >> reasonable size (and build time), as long as upstream doesn't help us > >> make smarter decisions. Useless modules aren't free, they aren't even > >> cheap. > > FWIW, we did that policy changed in Fedora a while ago. Not > wholesale, but if it looks niche, it's disabled by default and enabled > only on request. > > > I'd argue that your build systems need to get faster, the laptop I'm > > typing this on can do a full modconfig build, with over 3000 modules, in > > around 20 minutes. My build server in the cloud can do that in less > > than 5 minutes, and that's not a very fast machine these days. > > Is that literally 'make modconfig && make bzImage && make modules' in > those setups?
Yes, I use ktest with the allmodconfig option.
> I'm curious if the distros have some options enabled > that significantly impact build time. Perhaps CONFIG_DEBUG_INFO or > something else like that. Could you send me whatever config results > from what you're building in 5min?
You can use ktest with the BUILD_TYPE set to allmodconfig and it will reproduce the same options.
> It takes my desktop machine about 30-45min to build an x86_64 kernel > RPM with the current configs. Now granted, that's a bit more than > just building a kernel in a local git tree, but it's nowhere near > 5min. Our official build servers show similar timings for x86_64. > > For ARM kernels, it takes about 3.5-4 hours. That's due to policy > decisions on now allowing cross-builds in the distro (sigh), so all of > the kernels are built on native ARM machines.
That's really crazy to do that, there is this wonderful tool called qemu... :)
good luck,
greg k-h
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