On Wed, 2020-10-28 at 13:57 +0100, Joerg Schilling via austin-group-l
at The Open Group wrote:
> Yes, the speudo target .WAIT has been introduced into SunPro Make
> with Solaris 2 and it pemits to get fine grained control to parallel
> execution
>
> If GNU make did implement it as well, this would be a real benefit
> for controllability and portablity.
I have no objection to having this feature implemented in GNU make;
however, it is not a simple enhancement and so would require some
significant effort.
> Since .NOTPARALLEL seems to just overwrite the -j# command line
> option from GNU make by -j1, this does not seem to be hard to
> implement in SunPro Make.
That's not really what it does. In fact, it doesn't change the command
line options at all; that would not be good.
Setting .NOTPARALLEL in the current instance of make doesn't impact any
sub-makes that are invoked; they will still be run in parallel unless
they also define .NOTPARALLEL in their makefile.
Basically setting .NOTPARALLEL is checked in one place in the GNU make
code:
if (job_slots == 1 || not_parallel)
/* Since there is only one job slot, make things run linearly.
So it does not change the configuration of make, it only adds an extra
check for .NOTPARALLEL alongside the normal check for number of jobs.
