Until now, graph-depends was calling "make <pkg>-show-depends"
individually for eack package, which was very slow. Now, it calls
"make <pkg1>-show-depends <pkg2>-show-depends ... <pkgN>-show-depends"
for all packages it knows, and then does that recursively. It reduces
the number of make invocations to the deepest dependency chain in the
current configuration, instead of having a number of make invocations
equal to the number of enabled packages.
For a configuration with xvkbd enabled (which brings a significant
number of X.org dependencies) and a tar root filesystem, the time to
execute graph-depends was:
real 5m14.944s
user 4m53.590s
sys 0m14.069s
After our optimizations, it is now:
real 0m33.096s
user 0m30.878s
sys 0m1.472s
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
4359685e14