svn commit: r291744 - in head/sys: conf modules

[John Baldwin]

On Friday, December 04, 2015 04:27:21 AM Bryan Drewery wrote:
> Author: bdrewery
> Date: Fri Dec  4 04:27:21 2015
> New Revision: 291744
> URL: https://svnweb.freebsd.org/changeset/base/291744
> 
> Log:
>   Calculate MPATH for sys/modules to save 92% time in a basic 'obj' tree-walk.
>   
>   Sponsored by:	EMC / Isilon Storage Division
> 
> Modified:
>   head/sys/conf/kmod.mk
>   head/sys/modules/Makefile
> 
> Modified: head/sys/conf/kmod.mk
> ==============================================================================
> --- head/sys/conf/kmod.mk	Fri Dec  4 03:54:18 2015	(r291743)
> +++ head/sys/conf/kmod.mk	Fri Dec  4 04:27:21 2015	(r291744)
> @@ -370,8 +370,10 @@ vnode_if_typedef.h:
>  .endif
>  
>  # Build _if.[ch] from _if.m, and clean them when we're done.
> +# This is duplicated in sys/modules/Makefile.
>  .if !defined(__MPATH)
>  __MPATH!=find ${SYSDIR:tA}/ -name \*_if.m
> +.export __MPATH
>  .endif
>  _MFILES=${__MPATH:T:O}
>  _MPATH=${__MPATH:H:O:u}

It's also duplicated in sys/conf/kern.pre.mk which uses this to export it:

# Calculate path for .m files early, if needed.
.if !defined(__MPATH)
__MPATH!=find ${S:tA}/ -name \*_if.m
.endif
....
MKMODULESENV+=  __MPATH="${__MPATH}"

So, the comment should probably reference the two other places that will pass
an __MPATH down (kern.pre.mk and sys/modules/Makefile).

Note though that you should only be seeing this if you are building modules
outside of a kernel build (e.g. MODULES_WITH_WORLD).  modules built as part of
a kernel build will inherit __MPATH from kern.pre.mk.

When I ran a buildkernel with truss -af and grepp'd for all the execve's of
/usr/bin/find I only found about 6 for a GENERIC kernel, so I believe that
the kern.pre.mk bits were working already.

-- 
John Baldwin