Evaluating a macro argument only if certain configuration options
have been selected is confusing and error-prone. Hence always
evaluate the second argument of spin_lock_nested() and
spin_lock_nest_lock().
This patch has the intentional side effect that it avoids that the
following warning is reported for netif_addr_lock_nested() when
building with CONFIG_DEBUG_LOCK_ALLOC=n and with W=1:
include/linux/netdevice.h: In function 'netif_addr_lock_nested':
include/linux/netdevice.h:2865:6: warning: variable 'subclass' set but not used
[-Wunused-but-set-variable]
int subclass = SINGLE_DEPTH_NESTING;
^
Signed-off-by: Bart Van Assche <bvanass...@acm.org>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: David S. Miller <da...@davemloft.net>
---
include/linux/spinlock.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 3f2867f..32b16cc 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -197,8 +197,10 @@ static inline void do_raw_spin_unlock(raw_spinlock_t
*lock) __releases(lock)
_raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
} while (0)
#else
-# define raw_spin_lock_nested(lock, subclass) _raw_spin_lock(lock)
-# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock)
+# define raw_spin_lock_nested(lock, subclass) \
+ ((void)(subclass), _raw_spin_lock(lock))
+# define raw_spin_lock_nest_lock(lock, nest_lock) \
+ ((void)(nest_lock), _raw_spin_lock(lock))
#endif
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
--
1.8.4.5
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
