[PATCH] Add MAXCPU as a kernel config option and quality discussion on this

[mdf at FreeBSD.org]

On Fri, Jul 8, 2011 at 8:37 AM, Attilio Rao <attilio at freebsd.org> wrote:
> I've made this patch for making MAXCPU a kernel config option:
> http://www.freebsd.org/~attilio/maxcpu_kernel_opt.diff
>
> Besides if this is a good idea or not (which I think it is) I want to
> discuss this implementation and similar related problems.
> In this case I've been forced to include opt_maxcpu.h in all the MD
> param.h implementations. A similar case, KSTACK_PAGES, includes the
> opt_kstack_pages.h only in the consumers. While this is possible for
> KSTACK_PAGES, because there are very little consumers, it would be
> impratical for MAXCPU. Besides, this is a very dangerous practice
> IMHO: if a consumer fails to add opt_kstack_pages it may end up with a
> faulty value, introducing a breakage that would go unnoticed.
>
> In my case, I think that including opt_maxcpu is a viable panacea, but
> in general, after discussing with peter@, probabilly the better idea
> would be having a centralized script that does pre-processing before
> to start compiling and set with the right values all those constants
> (something like genassym.c, but of course with a different purpose).
>
> What are your ideas on that? Do you think that including opt_maxcpu.h
> would be acceptable for the time being?

Isn't MAXCPU used frequently enough that it should be in opt_global.h?
 Or are we discouraging the use of opt_global.h and of MAXCPU such
that that's not a practical solution?

Thanks,
matthew