Re: parallelism in the module-level, generated GNUmakefile's

["Gao, Liming" <liming.gao@intel.com>]

Yes. BaseTools should make sure the complete dependency in the generated Makefile. If you find any missing, please submit BZs. 

> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Thursday, January 24, 2019 6:07 AM
> To: Gao, Liming <liming.gao@intel.com>
> Cc: edk2-devel-01 <edk2-devel@lists.01.org>
> Subject: Re: [edk2] parallelism in the module-level, generated GNUmakefile's
> 
> On 01/23/19 17:36, Gao, Liming wrote:
> > Laszlo: By design, BaseTools generates GNUMakefile with the complete
> > dependency. So, the generated GNUMakefile should support parallelism
> > run. But, I don't verify this functionality. Have you found any
> > limitation to forbid parallelism run in module GNUMakefile?
> 
> No, I haven't, and that is what surprised me :) I *expected* problems,
> but didn't find any.
> 
> Given that BaseTools / "build" does not offer any way at all to build a
> single generated  GNUMakefile with "make -j", such parallel builds of
> said GNUMakefiles have never been tested.
> 
> Therefore, I expected them to break, under "make -j".
> 
> When they didn't, I was surprised. :)
> 
> The question is if we can *rely* on BaseTools to generate the
> GNUMakefiles with complete dependencies.
> 
> In other words, if we now start building them with "make -j" (via the
> outer make), and run into an error due to missing dependencies, can we
> report a TianoCore BZ about that? Will it be in scope? Is "complete
> dependencies" an explicit goal?
> 
> If the answer is "yes", I will happily take that answer.
> 
> If the answer is "no", then BaseTools should use .NOTPARALLEL in the
> GNUMakefiles (or else "build" should invoke the inner "make" with an
> explicit "-j1" flag -- as I've learned today).
> 
> Thank you!
> Laszlo