Commit 91c63ecd authored by Michal Hocko's avatar Michal Hocko Committed by Linus Torvalds
Browse files

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: default avatarMichal 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent dcda9b04
......@@ -54,6 +54,16 @@ kmem_flags_convert(xfs_km_flags_t flags)
lflags &= ~__GFP_FS;
}
/*
* Default page/slab allocator behavior is to retry for ever
* for small allocations. We can override this behavior by using
* __GFP_RETRY_MAYFAIL which will tell the allocator to retry as long
* as it is feasible but rather fail than retry forever for all
* request sizes.
*/
if (flags & KM_MAYFAIL)
lflags |= __GFP_RETRY_MAYFAIL;
if (flags & KM_ZERO)
lflags |= __GFP_ZERO;
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment