xfs: map KM_MAYFAIL to __GFP_RETRY_MAYFAIL
authorMichal Hocko <mhocko@suse.com>
Wed, 12 Jul 2017 21:36:49 +0000 (14:36 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 12 Jul 2017 23:26:03 +0000 (16:26 -0700)
commit91c63ecda75d3004da8ffd5d2590383e0ba47722
tree4a8feb38b5ea9dc4178369cca725dc317dd56f9c
parentdcda9b04713c3f6ff0875652924844fae28286ea
xfs: map KM_MAYFAIL to __GFP_RETRY_MAYFAIL

KM_MAYFAIL didn't have any suitable GFP_FOO counterpart until recently
so it relied on the default page allocator behavior for the given set of
flags.  This means that small allocations actually never failed.

Now that we have __GFP_RETRY_MAYFAIL flag which works independently on
the allocation request size we can map KM_MAYFAIL to it.  The allocator
will try as hard as it can to fulfill the request but fails eventually
if the progress cannot be made.  It does so without triggering the OOM
killer which can be seen as an improvement because KM_MAYFAIL users
should be able to deal with allocation failures.

Link: http://lkml.kernel.org/r/20170623085345.11304-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alex Belits <alex.belits@cavium.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Daney <david.daney@cavium.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: NeilBrown <neilb@suse.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/xfs/kmem.h