Re: Patch for Makefile race against current cvs

On Fri, 9 Nov 2001, Tom Lane wrote:

> Klaus Naumann <knaumann@gmx-ag.de> writes:
> > Yes, I also have seen races in two other directories
> > (and decided to change all occorences of the two-file
> > target in any Makefile because I'm under the impression
> > that it's to dangerous ...).
>
> Now you're back to saying that any two-target rule is unsafe under
> parallel make.  I find that hard to believe, given the lack of any
> suggestion in the gmake documents that any care needs to be taken
> to make things safe for parallel makes.

At least the last sentence is just plain wrong. I have seen
and heard of several projects which had to change their
Makefiles to make parallel builds work.
A good example would be the linux kernel.
If you do a make -j3 dep clean bzImage you really f*ck up things
as it's all done in parallel. If you would add a rule

anything: dep clean bzImage

things would get messed up too (I have tried it ...).
I don't count this as a bug in make ...

And no, I'm not saying that any two-target rule is unsafe,
I just said I removed all as I think that it's a good idea
to aviod possible problems which might occur in the future.

    CU, Klaus

--
Klaus Naumann
Systems Administration
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