[tip:locking/core] locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK

From: tip-bot for Davidlohr Bueso
Date: Thu Jun 05 2014 - 10:34:54 EST


Commit-ID: dbb5eafa23fdb7a00d64b04e23a3efc59d6474cb
Gitweb: http://git.kernel.org/tip/dbb5eafa23fdb7a00d64b04e23a3efc59d6474cb
Author: Davidlohr Bueso <davidlohr@xxxxxx>
AuthorDate: Mon, 19 May 2014 17:27:57 -0700
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 5 Jun 2014 10:38:45 +0200

locking/rwsem: Fix warnings for CONFIG_RWSEM_GENERIC_SPINLOCK

Optimistic spinning is only used by the xadd variant
of rw-semaphores. Make sure that we use the old version
of the __RWSEM_INITIALIZER macro for systems that rely
on the spinlock one, otherwise warnings can be triggered,
such as the following reported on an arm box:

ipc/ipcns_notifier.c:22:8: warning: excess elements in struct initializer [enabled by default]
ipc/ipcns_notifier.c:22:8: warning: (near initialization for 'ipcns_chain.rwsem') [enabled by default]
ipc/ipcns_notifier.c:22:8: warning: excess elements in struct initializer [enabled by default]
ipc/ipcns_notifier.c:22:8: warning: (near initialization for 'ipcns_chain.rwsem') [enabled by default]

Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
Cc: Alex Shi <alex.shi@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Jason Low <jason.low2@xxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Josef Bacik <jbacik@xxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1400545677.6399.10.camel@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/rwsem.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 3e108f1..8d79708 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -64,7 +64,7 @@ static inline int rwsem_is_locked(struct rw_semaphore *sem)
# define __RWSEM_DEP_MAP_INIT(lockname)
#endif

-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) && !defined(CONFIG_RWSEM_GENERIC_SPINLOCK)
#define __RWSEM_INITIALIZER(name) \
{ RWSEM_UNLOCKED_VALUE, \
__RAW_SPIN_LOCK_UNLOCKED(name.wait_lock), \
--
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