depend + all vs dependall

Bruce Evans bde at zeta.org.au
Sun Mar 30 23:04:52 PST 2003


On Mon, 31 Mar 2003, Ruslan Ermilov wrote:

> On Sat, Mar 29, 2003 at 04:33:43PM -0700, M. Warner Losh wrote:
> ...
> > @@ -67,7 +67,7 @@
> >
> >
> >  .for __target in all all-man checkdpadd clean cleandepend cleandir \
> > -    depend distribute lint maninstall \
> > +    depend dependall distribute lint maninstall \
> >      obj objlink realinstall regress tags
> >  ${__target}: _SUBDIR
> >  .endfor
>
> If you want to really try dependall, you should implement it
> in bsd.subdir.mk like the distribute target, similar to this:
>
> .if !target(dependall)
> dependall:
>         cd ${.CURDIR}; \
>             ${MAKE} depend -DNO_SUBDIR; \
>             ${MAKE} all -DNO_SUBDIR
> .endif

That won't work, since it gives a double tree traversal for the
subdirs and thus defeats the point of dependall.  Any splitting
up of dependall must not be passed down.

> Also, your test is not honest because original Makefile.inc1
> did not parallelize the "all" stage of "buildworld", by not
> implementing par-all.  Last time I tried par-all, it saved
> me 16% of time from the -j8 buildworld:
>
> 26m8.74s real           26m13.08s user          11m9.70s sys (old)
> 21m48.52s real          26m20.60s user          11m4.95s sys (new)
>
> Attached is the message with the patch.  It has some Russian,
> but also includes a patch.  Note that par-all only parallelizes
> top-level bsd.subdir.mk makefiles, as we depend on the ordering
> of traversing SUBDIRs in a few places.  The plan is to drop
> this assumption in places that don't need this ordering.

Please benchmark mainly for the usual case of non-SMP :-).

Bruce


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