Re: filemon: weird full-time build although filemon enabled

> On May 6, 2017, at 00:22, O. Hartmann <ohartmann_at_walstatt.org> wrote:
> 
> I build CURRENT on two technically similar systems on a almost daily basis. Therefore, it
> was a great relief having WITH_META_MODE=yes set in /etc/src-env.conf for incremental
> builds. To make my understanding of this clear (just in case I'm wrong): setting
> WITH_META_MODE builds only portions that does not need to be build in the make context.
> 
> Well, the reason writing this email is: on one system, I run almost every reboot into a
> "full build" and this puzzles me a bit. The long-lasting and time exhausting builds are
> within the LLVM/CLANG tree. They consume a lot of time. The box in question does have a
> weak CPU, only two physical cores, four threads, 8GB of RAM and builds the /usr/obj
> residing on a SSD. The reference machine does have the same motherboard, also a SSD, but
> has 16 GB RAM and a 4-core/8 threads XEON CPU - but both are "IvyBridge". The XEON
> usually needs 30 - 40 minutes to compile a full world/kernel from a clean /usr/obj, the
> "weak" box takes approximately 120 minutes - it is understandable that a shortage of the
> build time is appreciated.
> 
> Well, having said this, I need to mention that both systems use almost
> identical /etc/src.conf setting - except the order of appearance of the WITH_ tags. In
> fact, they are identical except the KERNCONF (naming of the kernel) and PORTS_MODULES=,
> the "weak" box incorporates x11/nvidia-driver and emulators/virtualbox-ose-kmod, so these
> modules are build every time the system gets rebuild, but the time taken by those is
> negligible.
> 
> The problem: to make my point clear: the "weak" box starts compiling almost everytime now
> the LLVM/CLANG tree while the XEON box does not. This is spooky.
> 
> I deleted on both  systems recently /usr/obj completely from its content and restarted a
> buildworld again to hope, that the problem was introduced due to some files
> necessary for the BSD make environment to indicate the incremental build. But no success.
> Even more spooky is the fact, that after a build on the "weak" box and a build again, the
> box bevaves as expected not rebuilding everything again, but in some cases after a
> reboot, a rebuild the hits again the build of LLVM/CLANG tree, while the XEON box does
> not.
> 
> I think there is something missing an I'd like to ask what is the suggested way to
> initially restart a full build to ensure that WITH_META_MODE gets initialised correctly.
> 
> Well, I'm not a developer, so please be patient with my naive report.
> 
> Thanks in advance,

	Dumb question: which kernel are you using on which machine (GENERIC, GENERIC-NODEBUG, a custom kernel with or without debug hooks, e.g., INVARIANTS, enabled)? Also, how are you building the system (locally using UFS or ZFS, remotely, e.g., over NFS, etc)?
Thanks,
-Ngie