workqueue: add args to workqueue lockdep name

Tommi noticed a 'funny' lock class name: "%s#5" from a lock acquired in
process_one_work().

Maybe #fmt plus #args could be used as the lock_name to give some more
information for some fmt string like the above.

__builtin_constant_p() check is removed (as there seems no good way to
check all the variables in args list). However, by removing the check,
it only adds two additional "s for those constants.

Some lockdep name examples printed out after the change:

lockdep name                    wq->name

"events_long"                   events_long
"%s"("khelper")                 khelper
"xfs-data/%s"mp->m_fsname       xfs-data/dm-3

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 594521b..704f4f6 100644 (file)
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -419,10 +419,7 @@ __alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
        static struct lock_class_key __key;                             \
        const char *__lock_name;                                        \
                                                                        \
-       if (__builtin_constant_p(fmt))                                  \
-               __lock_name = (fmt);                                    \
-       else                                                            \
-               __lock_name = #fmt;                                     \
+       __lock_name = #fmt#args;                                        \
                                                                        \
        __alloc_workqueue_key((fmt), (flags), (max_active),             \
                              &__key, __lock_name, ##args);             \