workqueue: make alloc_workqueue() take printf fmt and args for name
alloc_workqueue() currently expects the passed in @name pointer to remain
accessible. This is inconvenient and a bit silly given that the whole wq
is being dynamically allocated. This patch updates alloc_workqueue() and
friends to take printf format string instead of opaque string and matching
varargs at the end. The name is allocated together with the wq and
formatted.
alloc_ordered_workqueue() is converted to a macro to unify varargs
handling with alloc_workqueue(), and, while at it, add comment to
alloc_workqueue().
None of the current in-kernel users pass in string with '%' as constant
name and this change shouldn't cause any problem.
[akpm@linux-foundation.org: use __printf]
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 0d556de..eb8b9f1 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -297,32 +297,50 @@
extern struct workqueue_struct *system_freezable_wq;
extern struct workqueue_struct *
-__alloc_workqueue_key(const char *name, unsigned int flags, int max_active,
- struct lock_class_key *key, const char *lock_name);
+__alloc_workqueue_key(const char *fmt, unsigned int flags, int max_active,
+ struct lock_class_key *key, const char *lock_name, ...) __printf(1, 6);
+/**
+ * alloc_workqueue - allocate a workqueue
+ * @fmt: printf format for the name of the workqueue
+ * @flags: WQ_* flags
+ * @max_active: max in-flight work items, 0 for default
+ * @args: args for @fmt
+ *
+ * Allocate a workqueue with the specified parameters. For detailed
+ * information on WQ_* flags, please refer to Documentation/workqueue.txt.
+ *
+ * The __lock_name macro dance is to guarantee that single lock_class_key
+ * doesn't end up with different namesm, which isn't allowed by lockdep.
+ *
+ * RETURNS:
+ * Pointer to the allocated workqueue on success, %NULL on failure.
+ */
#ifdef CONFIG_LOCKDEP
-#define alloc_workqueue(name, flags, max_active) \
+#define alloc_workqueue(fmt, flags, max_active, args...) \
({ \
static struct lock_class_key __key; \
const char *__lock_name; \
\
- if (__builtin_constant_p(name)) \
- __lock_name = (name); \
+ if (__builtin_constant_p(fmt)) \
+ __lock_name = (fmt); \
else \
- __lock_name = #name; \
+ __lock_name = #fmt; \
\
- __alloc_workqueue_key((name), (flags), (max_active), \
- &__key, __lock_name); \
+ __alloc_workqueue_key((fmt), (flags), (max_active), \
+ &__key, __lock_name, ##args); \
})
#else
-#define alloc_workqueue(name, flags, max_active) \
- __alloc_workqueue_key((name), (flags), (max_active), NULL, NULL)
+#define alloc_workqueue(fmt, flags, max_active, args...) \
+ __alloc_workqueue_key((fmt), (flags), (max_active), \
+ NULL, NULL, ##args)
#endif
/**
* alloc_ordered_workqueue - allocate an ordered workqueue
- * @name: name of the workqueue
+ * @fmt: printf format for the name of the workqueue
* @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
+ * @args: args for @fmt
*
* Allocate an ordered workqueue. An ordered workqueue executes at
* most one work item at any given time in the queued order. They are
@@ -331,11 +349,8 @@
* RETURNS:
* Pointer to the allocated workqueue on success, %NULL on failure.
*/
-static inline struct workqueue_struct *
-alloc_ordered_workqueue(const char *name, unsigned int flags)
-{
- return alloc_workqueue(name, WQ_UNBOUND | flags, 1);
-}
+#define alloc_ordered_workqueue(fmt, flags, args...) \
+ alloc_workqueue(fmt, WQ_UNBOUND | (flags), 1, ##args)
#define create_workqueue(name) \
alloc_workqueue((name), WQ_MEM_RECLAIM, 1)