Re: [pcp] pcp update: more make -j support

["Frank Ch. Eigler" <fche@xxxxxxxxxx>]

Hi, Mark -

Thanks for taking a look!

> [...]
> Hi Frank, on my 4-core RHEL7.1 box, your fche/make-j tree builds :
> real  8m16.531s
> [...]
> Compared to current master branch :
> real  10m9.608s
> [...]

Yeah; the %{_smp_mflags} underestimates the available parallelism; the
load average here rarely gets close to the number-of-cpus.  2 x #cpus
that makes things faster on my 4/8-cpu boxes.


> So the changes look good - reviewing the code the need for the '+'
> prefix on certain rules wasn't obvious (I know about '@' to suppress
> echo but not '+'). [...]

The '+' seems to be a hint to gnu-make that nested $(MAKE)s should be
specially treated; see [1].

[1] https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html

- FChE