percpu: fix too low alignment restriction on UP

UP __alloc_percpu() triggered WARN_ON_ONCE() if the requested
alignment is larger than that of unsigned long long, which is too
small for all the cacheline aligned allocations.  Bump it up to
SMP_CACHE_BYTES which kmalloc allocations generally guarantee.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index d8e5a9a..545b068 100644 (file)
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -156,7 +156,7 @@ static inline void *__alloc_percpu(size_t size, size_t align)
         * on it.  Larger alignment should only be used for module
         * percpu sections on SMP for which this path isn't used.
         */
-       WARN_ON_ONCE(align > __alignof__(unsigned long long));
+       WARN_ON_ONCE(align > SMP_CACHE_BYTES);
        return kzalloc(size, GFP_KERNEL);
 }