The patch titled
Subject: xfs: map KM_MAYFAIL to __GFP_RETRY_MAYFAIL
has been removed from the -mm tree. Its filename was
xfs-map-km_mayfail-to-__gfp_retry_mayfail.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Alex Belits <alex.belits@xxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: NeilBrown <neilb@xxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/xfs/kmem.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff -puN fs/xfs/kmem.h~xfs-map-km_mayfail-to-__gfp_retry_mayfail fs/xfs/kmem.h
--- a/fs/xfs/kmem.h~xfs-map-km_mayfail-to-__gfp_retry_mayfail
+++ a/fs/xfs/kmem.h
@@ -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;
_
Patches currently in -mm which might be from mhocko@xxxxxxxx are
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