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/kernel/workqueue.c b/kernel/workqueue.c
index 42fa9ad..bec7b5b 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -242,10 +242,10 @@
int nr_drainers; /* W: drain in progress */
int saved_max_active; /* W: saved cwq max_active */
- const char *name; /* I: workqueue name */
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
+ char name[]; /* I: workqueue name */
};
struct workqueue_struct *system_wq __read_mostly;
@@ -2954,14 +2954,29 @@
return clamp_val(max_active, 1, lim);
}
-struct workqueue_struct *__alloc_workqueue_key(const char *name,
+struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
unsigned int flags,
int max_active,
struct lock_class_key *key,
- const char *lock_name)
+ const char *lock_name, ...)
{
+ va_list args, args1;
struct workqueue_struct *wq;
unsigned int cpu;
+ size_t namelen;
+
+ /* determine namelen, allocate wq and format name */
+ va_start(args, lock_name);
+ va_copy(args1, args);
+ namelen = vsnprintf(NULL, 0, fmt, args) + 1;
+
+ wq = kzalloc(sizeof(*wq) + namelen, GFP_KERNEL);
+ if (!wq)
+ goto err;
+
+ vsnprintf(wq->name, namelen, fmt, args1);
+ va_end(args);
+ va_end(args1);
/*
* Workqueues which may be used during memory reclaim should
@@ -2978,12 +2993,9 @@
flags |= WQ_HIGHPRI;
max_active = max_active ?: WQ_DFL_ACTIVE;
- max_active = wq_clamp_max_active(max_active, flags, name);
+ max_active = wq_clamp_max_active(max_active, flags, wq->name);
- wq = kzalloc(sizeof(*wq), GFP_KERNEL);
- if (!wq)
- goto err;
-
+ /* init wq */
wq->flags = flags;
wq->saved_max_active = max_active;
mutex_init(&wq->flush_mutex);
@@ -2991,7 +3003,6 @@
INIT_LIST_HEAD(&wq->flusher_queue);
INIT_LIST_HEAD(&wq->flusher_overflow);
- wq->name = name;
lockdep_init_map(&wq->lockdep_map, lock_name, key, 0);
INIT_LIST_HEAD(&wq->list);
@@ -3020,7 +3031,8 @@
if (!rescuer)
goto err;
- rescuer->task = kthread_create(rescuer_thread, wq, "%s", name);
+ rescuer->task = kthread_create(rescuer_thread, wq, "%s",
+ wq->name);
if (IS_ERR(rescuer->task))
goto err;
