Re: [ia64:noboot 4/4] mm/page_alloc.c:321:14: error: 'PAGES_PER_SECTION' undeclared; did you mean 'U

[Mike Rapoport <rppt@linux.vnet.ibm.com>]

On Fri, Jul 27, 2018 at 07:08:40PM +0000, Luck, Tony wrote:
> >> mm/page_alloc.c:321:14: error: 'PAGES_PER_SECTION' undeclared (first use in this function); did you mean 'USEC_PER_SEC'?
> 
> Weird.  I unpacked that config file and tried to reproduce ... but got a clean build.
> 
> Maybe my build flipped some other options because I'm using an ancient compiler?
> I noticed this difference at the top of the output when I diffed my .config with the
> supplied one:
> 
> < CONFIG_GCC_VERSION€100
> ---
> > CONFIG_GCC_VERSION@304
> 
> Mike: Did you see anything like this when you did cross builds?
 
Yep, and I think it's not related to the compiler version. Selecting
NO_BOOTMEM allows enabling the DEFERRED_STRUCT_PAGE_INIT option that in
turn causes compilation of the code that uses PAGES_PER_SECTION.  The
definition of PAGES_PER_SECTION, though, depends on SPARSEMEM which is not
enabled in allmconfig for ia64.

I've sent a patch [1] to make DEFERRED_STRUCT_PAGE_INIT depend on
SPARSEMEM, it's landed in the akmp tree.

[1] https://lore.kernel.org/lkml/1530279308-24988-1-git-send-email-rppt@linux.vnet.ibm.com/#t

> -Tony
> 
> 

-- 
Sincerely yours,
Mike.