[CFT] WITH_META_MODE: Working incremental build [only on i386 and amd64]

[Mark Millard]

Quoting the original note about WITH_META_MODE ( https://lists.freebsd.org/pipermail/freebsd-current/2016-May/061481.html ):

> You will also need to load the filemon(4) module with 'kldload filemon'.

But head's sys/modules/Makefile says:

> .if defined(MODULES_OVERRIDE) && !defined(ALL_MODULES)
> SUBDIR=${MODULES_OVERRIDE}
> .else
> SUBDIR= \

. . .
>        ${_filemon} \

. . .
> .if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"
. . .
> _filemon=       filemon
. . .

as the only contexts that provide a filemon.ko to use with kldload.

Thus, for example, arm variants (32 bit and 64 bit) and powerpc variants (32bit and 64 bit) do not have WITH_META_MODE as an option as things are set up.

I had been hoping to cut down on the time for clang-related rebuilds during native buildworld runs on my slower buildworld contexts (armv7a/cortex-a7, powerpc, powerpc64). But it was not to be.

It appears that, once some arm variants are officially tier 1, WITH_META_MODE will not span all tier 1 platforms.

[Since I tend to use non-tier-1 platforms I tend to notice some of the statements about FreeBSD that are true of only tier 1 without being explicit about it. But initially it takes some research to discover that status for each such point. WITH_META_MODE is an example.]

===
Mark Millard
markmi at dsl-only.net