[tip:master 30/35] mm/memory.c:72:2: warning: #warning Unfortunate NUMA config, growing page-frame f

[tip:master 30/35] mm/memory.c:72:2: warning: #warning Unfortunate NUMA config, growing page-frame f

[Fengguang Wu]

Hi Peter,

FYI, there are new compile warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master
head:   2ef756a2e79149dc84c88f7ccc42ec38cbb7722e
commit: 835e3cf29f4eeba6c5c8bcc188b2138029157938 [30/35] mm: Fold page::nid_last into page::flags when possible
config: i386-allmodconfig

All warnings:

mm/memory.c:72:2: warning: #warning Unfortunate NUMA config, growing page-frame for last_nid. [-Wcpp]

vim +72 mm/memory.c

42b77728 (Jan Beulich     2008-07-23  69) #include "internal.h"
42b77728 (Jan Beulich     2008-07-23  70) 
835e3cf2 (Peter Zijlstra  2012-08-13  71) #ifdef LAST_NID_NOT_IN_PAGE_FLAGS
835e3cf2 (Peter Zijlstra  2012-08-13 @72) #warning Unfortunate NUMA config, growing page-frame for last_nid.
835e3cf2 (Peter Zijlstra  2012-08-13  73) #endif
835e3cf2 (Peter Zijlstra  2012-08-13  74) 
d41dee36 (Andy Whitcroft  2005-06-23  75) #ifndef CONFIG_NEED_MULTIPLE_NODES
^1da177e (Linus Torvalds  2005-04-16  76) /* use the per-pgdat data instead for discontigmem - mbligh */
^1da177e (Linus Torvalds  2005-04-16  77) unsigned long max_mapnr;
^1da177e (Linus Torvalds  2005-04-16  78) struct page *mem_map;
^1da177e (Linus Torvalds  2005-04-16  79) 
^1da177e (Linus Torvalds  2005-04-16  80) EXPORT_SYMBOL(max_mapnr);

---
0-DAY kernel build testing backend         Open Source Technology Centre
Fengguang Wu, Yuanhan Liu                              Intel Corporation

Re: [tip:master 30/35] mm/memory.c:72:2: warning: #warning Unfortunate NUMA config, growing page-fra

[Peter Zijlstra]

On Fri, 2012-09-28 at 17:55 +0800, Fengguang Wu wrote:
> Hi Peter,
> 
> FYI, there are new compile warnings show up in
> 
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git master
> head:   2ef756a2e79149dc84c88f7ccc42ec38cbb7722e
> commit: 835e3cf29f4eeba6c5c8bcc188b2138029157938 [30/35] mm: Fold page::nid_last into page::flags when possible
> config: i386-allmodconfig
> 
> All warnings:
> 
> mm/memory.c:72:2: warning: #warning Unfortunate NUMA config, growing page-frame for last_nid. [-Wcpp]

Yeah, 32bit NUMA config.. nobody sane should be doing or using that.

The other option was to hard-disable 32bit support for SCHED_NUMA, which
I wouldn't mind either.. who gives about 32 bits computing anyway ;-)