diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2009-06-16 15:32:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-16 19:47:40 -0700 |
| commit | dab48dab37d2770824420d1e01730a107fade1aa (patch) | |
| tree | 81e949d2521d4d8d979808feaa9c2a570337a98c /mm | |
| parent | 720b17e759a50635c429ccaa2ec3d01edb4f92d6 (diff) | |
page-allocator: warn if __GFP_NOFAIL is used for a large allocation
__GFP_NOFAIL is a bad fiction. Allocations _can_ fail, and callers should
detect and suitably handle this (and not by lamely moving the infinite
loop up to the caller level either).
Attempting to use __GFP_NOFAIL for a higher-order allocation is even
worse, so add a once-off runtime check for this to slap people around for
even thinking about trying it.
Cc: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 076463cb21ba..61290ea721c8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1128,6 +1128,19 @@ again: list_del(&page->lru); pcp->count--; } else { + if (unlikely(gfp_flags & __GFP_NOFAIL)) { + /* + * __GFP_NOFAIL is not to be used in new code. + * + * All __GFP_NOFAIL callers should be fixed so that they + * properly detect and handle allocation failures. + * + * We most definitely don't want callers attempting to + * allocate greater than single-page units with + * __GFP_NOFAIL. + */ + WARN_ON_ONCE(order > 0); + } spin_lock_irqsave(&zone->lock, flags); page = __rmqueue(zone, order, migratetype); __mod_zone_page_state(zone, NR_FREE_PAGES, -(1 << order)); |