tree 0925b5b584c8ed6718a54e6e56202686fb5b9468
parent ad8a1b558e6c76fb53901956d3c8f29b82a4ccfa
author David Rientjes <rientjes@google.com> 1326236858 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1326241843 -0800

mm, debug: test for online nid when allocating on single node

Calling alloc_pages_exact_node() means the allocation only passes the
zonelist of a single node into the page allocator.  If that node isn't
online, it's zonelist may never have been initialized causing a strange
oops that may not immediately be clear.

I recently debugged an issue where node 0 wasn't online and an allocator
was passing 0 to alloc_pages_exact_node() and it resulted in a NULL
pointer on zonelist->_zoneref.  If CONFIG_DEBUG_VM is enabled, though, it
would be nice to catch this a bit earlier.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>