This CL changes the behavior of 'make install' and 'make test'
in the src/cmd directory and the src/pkg directory to have
each recursive make clean up after itself immediately.
It does the same in test/run, removing $F.$A and $A.out
(the common byproducts) between runs.
On machines with slow disks and aggressive kernel caching,
cleaning up immediately can mean that the intermediate
objects never get written to disk.
This change eliminates almost all the disk waiting during
all.bash on my laptop (a Thinkpad X201s with an SSD running Linux).
147.50u 19.95s 277.34r before
148.53u 21.64s 179.59r after
R=golang-dev, r, iant2
CC=golang-dev
https://golang.org/cl/4413042
Using make -C $* rather than (cd $* ; make) results in a small,
but measurable improvement in build times where compilation is
not the major component. eg.
before - ~/go/src/pkg$ time make
real 0m1.176s
user 0m0.639s
sys 0m0.399s
after - ~/go/src/pkg$ time make
real 0m0.916s
user 0m0.571s
sys 0m0.243s
There are other places in the distribution src/make.common for example
that could also benefit from this change.
R=adg
CC=golang-dev, rsc
https://golang.org/cl/4174055
