[PATCH 0/5] Improve make and make check parallelism

[DJ Delorie]

Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> writes:
> Making the nptl's tests to additionally not overlap with other subdirs 
> (restore the old isolation), would need an explicit serialization edge 
> and that would erase much of the parallel-check speedup.

Maybe we want a new category for non-parallelizable tests?  We could
make that target .NOTPARALLEL at the top level (both the container
target and wildcard its contents).  There's no way to notparallel a
target in a subdirectory and have it apply across the build.

That might be a useful category to disable on small systems or when test
time must be minimized, too.