Wow - what a fantastic improvement. One thing I will caution though is for projects wanting to take code back to Solaris 10, they'll have to do two different types of Makefile changes. But really well worth the additional work
Chris Bill Sommerfeld wrote: > Some months ago I mentioned the world of hurt which comes out of the uts > makefiles using lots of wildcards to find source files. > > Last night I got inspired, did some prototyping, and I now have real > data on how much benefit we get from making the wildcards go away. > > While what I have is not even close to complete, the prototype has > already successfully built all sparc kernel modules (admittedly, I was > holding it together with the moral equivalent of duct tape and > clothespins. It flew to pieces when I attempted a nightly, but I > expected that). But the performance improvement is so dramatic I really > had to share this now.. > > One key microbenchmark relevant to developer productivity is the time it > takes to do an incremental build that doesn't actually build anything. > > Currently, on a 8x2x1.35ghz V890, a null build of uts/sun4u/genunix > takes: > > dmake 30.06s user 2.54s system 88% cpu 36.815 total > > With my prototype (which constructs a genunix which links > successfully...) I have it down to: > > dmake 2.65s user 0.41s system 81% cpu 3.735 total > > More importantly, a complete no-op build in usr/src/uts on the > aforementioned V890 takes just under 3 minutes. And that's without > Sasha's changes to increase parallelism. > > What's going on? Well, the hudnreds of wildcard rules in the various > Makefile.rules cause dmake to go hunting through hundreds of source > directories for each source file. > > If you expand the wildcards once -- which is straightforward to get 95% > right with a perl script because the *.rules files are so stylized -- > you eliminate all that hunting around. > > As always, there are a few weirdo special cases that need manual > cleanup; it also turns out that a bunch of the wildcard rules are either > duplicates or completely pointless (no source files matched). > > I filed > > 6613884 Wildcards in uts/.../Makefile.rules result in O(n^2) build > behavior > > Oh, in case anyone's wondering, it looks like my changes don't touch any > of the makefiles Sasha is changing. > > Making this real: > > I'm going to take the "mkrules" script, and split it in two. > > The first half will take a Makefile.rules file and generate an condensed > intermediate Makefile.rule.in file which will be human-maintainable and > which can be fed to the second script. > > The second half will take the *.in file and expand all the wildcards > into a "Makefile.rule" file. > > This project would: > add the scripts > add the Makefile.rule.in files > add rules to the top-level uts/Makefile to generate > Makefile.rule files > change everything that includes Makefile.rules to include > Makefile.rule instead > delete the Makefile.rules files. > > The reason for the rename to Makefile.rule is to avoid causing trouble > for projects which have unintegrated changes to Makefile.rules files > when this project integrates. > > - Bill > > > > _______________________________________________ > tools-discuss mailing list > tools-discuss@opensolaris.org > _______________________________________________ tools-discuss mailing list tools-discuss@opensolaris.org
