On Tue, 25 Oct 2011, Colin Cross wrote: > >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c > >> index fef8dc3..59cd4ff 100644 > >> --- a/mm/page_alloc.c > >> +++ b/mm/page_alloc.c > >> @@ -1786,6 +1786,13 @@ should_alloc_retry(gfp_t gfp_mask, unsigned int order, > >> return 0; > >> > >> /* > >> + * If PM has disabled I/O, OOM is disabled and reclaim is unlikely > >> + * to make any progress. To prevent a livelock, don't retry. > >> + */ > >> + if (!(gfp_allowed_mask & __GFP_FS)) > >> + return 0; > >> + > >> + /* > >> * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER > >> * means __GFP_NOFAIL, but that may not be true in other > >> * implementations. > > > > Eek, this is precisely what we don't want and is functionally the same as > > what you initially proposed except it doesn't care about __GFP_NOFAIL. > > This is checking against gfp_allowed_mask, not gfp_mask. > gfp_allowed_mask is initialized to GFP_BOOT_MASK to start so that __GFP_FS is never allowed before the slab allocator is completely initialized, so you've now implicitly made all early boot allocations to be __GFP_NORETRY even though they may not pass it.