If direct reclaim has failed to free memory, __GFP_NOFAIL allocations can potentially loop forever in the page allocator. In this case, it's better to give them the ability to access below watermarks so that they may allocate similar to the same privilege given to GFP_ATOMIC allocations.
We're careful to ensure this is only done after direct reclaim has had the chance to free memory, however. Signed-off-by: David Rientjes <rient...@google.com> --- mm/page_alloc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2629,6 +2629,11 @@ rebalance: pages_reclaimed)) { /* Wait for some write requests to complete then retry */ wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/50); + + /* Allocations that cannot fail must allocate from somewhere */ + if (gfp_mask & __GFP_NOFAIL) + alloc_flags |= ALLOC_HARDER; + goto rebalance; } else { /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/