diff options
| author | Michal Hocko <mhocko@suse.com> | 2017-07-11 01:50:12 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-11 02:32:33 +0300 |
| commit | 9d1f4b3f5b29bea431525e528a3ff2dc806ad904 (patch) | |
| tree | 651a2e2463e0f13b5adda660c849441f9c35eb01 /include/linux/mmzone.h | |
| parent | 3f906ba23689a3f824424c50f3ae937c2c70f676 (diff) | |
| download | linux-9d1f4b3f5b29bea431525e528a3ff2dc806ad904.tar.xz | |
mm: disallow early_pfn_to_nid on configurations which do not implement it
early_pfn_to_nid will return node 0 if both HAVE_ARCH_EARLY_PFN_TO_NID
and HAVE_MEMBLOCK_NODE_MAP are disabled. It seems we are safe now
because all architectures which support NUMA define one of them (with an
exception of alpha which however has CONFIG_NUMA marked as broken) so
this works as expected. It can get silently and subtly broken too
easily, though. Make sure we fail the compilation if NUMA is enabled
and there is no proper implementation for this function. If that ever
happens we know that either the specific configuration is invalid and
the fix should either disable NUMA or enable one of the above configs.
Link: http://lkml.kernel.org/r/20170704075803.15979-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 16532fa0bb64..fc14b8b3f6ce 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1055,6 +1055,7 @@ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) static inline unsigned long early_pfn_to_nid(unsigned long pfn) { + BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA)); return 0; } #endif |