[m-dev.] more changes for `--use-subdirs'

[Fergus Henderson]

On 20-Mar-1998, Peter Schachte <pets at students.cs.mu.oz.au> wrote:
> On Fri, 20 Mar 1998, Fergus Henderson wrote:
> 
> > Fix some problems with the `--use-subdirs' option.
> > With this change, the compiler itself now compiles
> > and bootstraps fine with MMAKE_USE_SUBDIRS=yes.
> 
> So are you going to tell us what difference this makes to mmake times?  Any
> perceptible difference?  I'll bet it makes a big difference when you do
> `ls'!

Times for `ls' in the compiler directory are ~0.15s with --use-subdirs
and ~2.0s with --no-use-subdirs.

But I haven't done much other timing yet.
So far I've just run a few timing tests in the library directory.
Times for `mmake depend' in the library directory go up, probably
because the generated .d files are bigger (I can fix this).
Times for `mmake' (once things have already been made, so this
is just the time for mmake to verify that everything is up-to-date)
seem to be about the same.

Raw data follows.

----------------------------------------------------------------------

Times for mmake in library directory, on murlibobo, using a local
filesystem (/home/mercury0), with Mmake.params containing

	EXTRA_CFLAGS=-g
	EXTRA_MLFLAGS=-g
	LIBRARY_RM_C=:
	RM_C=:

With --no-use-subdirs:

	mmake depend
		user 2.735, system 0.875, real 4.352, cpu usage 82.95%
		user 3.090, system 1.227, real 6.329, cpu usage 68.20%
		user 3.047, system 1.186, real 4.780, cpu usage 88.54%
		[load average: 4.21, 4.52, 4.59]

	mmake (from scratch)
		user 510.999, system 92.123, real 672.584, cpu usage 89.67%
		[load average: 4.93, 4.94, 4.72]
	mmake (do-nothing remake)
		user 0.831, system 2.867, real 3.730, cpu usage 99.14%
		user 0.730, system 2.812, real 3.494, cpu usage 100.00%
		user 0.724, system 2.885, real 3.615, cpu usage 99.82%

With --use-subdirs:

	mmake --use-subdirs depend
		user 3.072, system 2.639, real 8.607, cpu usage 66.36%
		user 3.341, system 2.788, real 8.719, cpu usage 70.29%
		user 3.279, system 2.757, real 7.736, cpu usage 78.02%
		[load average: 5.40, 4.83, 4.73]

	mmake --use-subdirs (do-nothing remake)
		user 0.649, system 2.867, real 3.686, cpu usage 95.41%
		user 0.619, system 2.257, real 4.149, cpu usage 69.32%
		user 0.592, system 1.853, real 2.800, cpu usage 87.34%

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3        |     -- the last words of T. S. Garp.