[xfs-masters] [PATCH 0/6] Handle bio_alloc failure

[Andrew Morton]

On Tue, 14 Apr 2009 14:16:32 -0400
Theodore Tso <tytso at mit.edu> wrote:

> In include/linux/page_alloc.h,
> __GFP_NOFAIL is documented as "will never fail", but it says
> absolutely nothing about __GFP_WAIT.

In the present implementation, a __GFP_WAIT allocation for order <=3
will only fail if the caller was oom-killed.

Which raises the question "what happens when a mempool_alloc() caller
gets oom-killed?".

Seems that it will loop around in mempool_alloc() doing weak attempts
to allocate memory, not doing direct reclaim while waiting for someone
else to free something up.  hm.  I guess it'll recover eventually.