Subject: bug#21066: Proceeding Order in AM generated Makefile

From: Mathieu Lirzin <[email-masked]>
Date: Sun, 16 Jul 2017 15:18:40 +0200

Hello,

Hans-Bernhard Bröker <[email-masked]> writes:

> Am 15.07.2015 um 17:10 schrieb Dilyan Palauzov:
>> http://lists.gnu.org/archive/html/bug-make/2015-07/msg00054.html
>> http://lists.gnu.org/archive/html/bug-make/2015-07/msg00055.html
>>
>> and tell me, if this is make or Automake problem.
>
> You've been told in the answer you already got that this is not,
> actually, a "problem".  You opted not to discuss that answer any
> further, and just to echo the question elsewhere instead.
>
> It's not make's job, much less automake's, to guess how long
> individual production rules might take.  The tree of dependencies is
> walked, that's it.

IIUC The observed problem is some lack of parallelism when running 'make
-jX'.  It is likely that Make derives the dependency graph between
targets solely from their prerequisites.  So any lack of parallelism
seems related to some unnecessary prerequisites added in the provided
rules.

I am closing this bug since this seems like a bug in the Makefile you
have written not in Automake.  Feel free to reopen it if you can provide
a minimal example demonstrating that the Make rules generated by
Automake could have more parallelism.

Thanks.

-- 
Mathieu Lirzin
GPG: F2A3 8D7E EB2B 6640 5761  070D 0ADE E100 9460 4D37