RE: Regression caused by Commit: 5bd7ad2b225b ("Preserve the real value of -jN in MAKEFLAGS using jobserver.")

[Gardell, Steven]

Our experience is that it is really only sensible as a top-level control. That 
said, it is convenient to have as an argument to make - which of course opens 
one up to seeing it specified on explicit sub-make invocations. I would also 
note that we have found that the performance behavior (this is real measured 
total build time) is rather tide to the output logging control so these two 
things need to be considered in tandem.

-----Original Message-----
From: Bug-make [mailto:address@hidden On Behalf Of NeilBrown
Sent: Monday, October 30, 2017 4:40 PM
To: Tim Murphy <address@hidden>; Paul D. Smith <address@hidden>
Cc: address@hidden
Subject: Re: Regression caused by Commit: 5bd7ad2b225b ("Preserve the real 
value of -jN in MAKEFLAGS using jobserver.")

On Mon, Oct 30 2017, Tim Murphy wrote:

> For my money -j is always a top-level setting.   To have it per makefile
> and then let makefiles depend on that behaviour would open the door to 
> lots of scary bugs.

I'm beginning to agree with this perspective.
The "-j" setting is not really a function of the code, it is a function of the 
hardware that make is being run on.
So I should set MAKEFLAGS=-j8 in my environment instead of if the Makefile.

Maybe we just need to change the documentation...

Thanks,
NeilBrown