Re: [Bug-apl] AM_MAKEFLAGS = -j 4

[Juergen Sauermann]

Hi Kacper,

what I tried was to remove the AM_MAKEFLAGS = -j 4 completely and then
make -j 4 clean all  at the top level. At the same time I watched the processes with top.

In the old build (with AM_MAKEFLAGS = -j 4), top normally shows up to 4 processes running  cc1plus.

After removing the AM_MAKEFLAGS = -j 4, I never saw more than one cc1plus process, even though
I did make -j 4 clean all at the top level. This might as well be caused by the way how automake
constructs the makefiles rather than by make itself. No idea what exactly is happening. But I suppose that
everybody is happy with the current solution.

/// Jürgen

On 07/29/2016 04:45 PM, Kacper Gutowski wrote:

On 29 July 2016 at 16:08, Juergen Sauermann wrote:

unfortunately it is not that easy. make does not pass its -j option to
sub-makes.

I don't know if it works as documented, I never checked it, but according
to GNU make manual, it should coordinate between sub-makes to run the
number of tasks in parallel as requested in top-level make invocation.
Passing down -j verbatim doesn't make sense because sub-makes are also
spawned in parallel so you would end up running more tasks than requested.
Manual also says it shall simply pass -j to sub makes when it's given
without a number to mean unlimited number of parallel tasks.

https://www.gnu.org/software/make/manual/html_node/Options_002fRecursion.html#index-job-slots_002c-and-recursion

-k