lib/rhashtable: guarantee initial hashtable allocation
rhashtable_init() may fail due to -ENOMEM, thus making the entire api unusable. This patch removes this scenario, however unlikely. In order to guarantee memory allocation, this patch always ends up doing GFP_KERNEL|__GFP_NOFAIL for both the tbl as well as alloc_bucket_spinlocks(). Upon the first table allocation failure, we shrink the size to the smallest value that makes sense and retry with __GFP_NOFAIL semantics. With the defaults, this means that from 64 buckets, we retry with only 4. Any later issues regarding performance due to collisions or larger table resizing (when more memory becomes available) is the least of our problems. Link: http://lkml.kernel.org/r/20180712185241.4017-9-manfred@colorfullife.com Signed-off-by:Davidlohr Bueso <dbueso@suse.de> Signed-off-by:
Manfred Spraul <manfred@colorfullife.com> Acked-by:
Herbert Xu <herbert@gondor.apana.org.au> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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93f976b5
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