>From 84b233adcca3cacd5cfa8013a5feda7a3db4a9af Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@xxxxxxxxxx>
Date: Fri, 18 Jan 2013 14:05:56 -0800
This function queries whether %current is an async worker executing an
async item. This will be used to implement warning on synchronous
request_module() from async workers.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
include/linux/async.h | 1 +
kernel/async.c | 14 ++++++++++++++
kernel/workqueue_internal.h | 11 +++++++++++
3 files changed, 26 insertions(+)
diff --git a/include/linux/async.h b/include/linux/async.h
index 7a24fe9..345169c 100644
--- a/include/linux/async.h
+++ b/include/linux/async.h
@@ -52,4 +52,5 @@ extern void async_synchronize_full_domain(struct async_domain *domain);
extern void async_synchronize_cookie(async_cookie_t cookie);
extern void async_synchronize_cookie_domain(async_cookie_t cookie,
struct async_domain *domain);
+extern bool current_is_async(void);
#endif
diff --git a/kernel/async.c b/kernel/async.c
index 9d31183..d9bf2a9 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -57,6 +57,8 @@ asynchronous and synchronous parts of the kernel.
#include <linux/slab.h>
#include <linux/workqueue.h>
+#include "workqueue_internal.h"
+
static async_cookie_t next_cookie = 1;
#define MAX_WORK 32768
@@ -337,3 +339,15 @@ void async_synchronize_cookie(async_cookie_t cookie)
async_synchronize_cookie_domain(cookie, &async_running);
}
EXPORT_SYMBOL_GPL(async_synchronize_cookie);
+
+/**
+ * current_is_async - is %current an async worker task?
+ *
+ * Returns %true if %current is an async worker task.
+ */
+bool current_is_async(void)
+{
+ struct worker *worker = current_wq_worker();
+
+ return worker && worker->current_func == async_run_entry_fn;
+}
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
index 02549fa..cc35e7e 100644
--- a/kernel/workqueue_internal.h
+++ b/kernel/workqueue_internal.h
@@ -8,6 +8,7 @@
#define _KERNEL_WORKQUEUE_INTERNAL_H
#include <linux/workqueue.h>
+#include <linux/kthread.h>
struct global_cwq;
struct worker_pool;
@@ -44,6 +45,16 @@ struct worker {
struct workqueue_struct *rescue_wq; /* I: the workqueue to rescue */
};
+/**
+ * current_wq_worker - return struct worker if %current is a workqueue worker
+ */
+static inline struct worker *current_wq_worker(void)
+{
+ if (current->flags & PF_WQ_WORKER)
+ return kthread_data(current);
+ return NULL;
+}
+
/*
* Scheduler hooks for concurrency managed workqueue. Only to be used from
* sched.c and workqueue.c.
--
1.8.0.2
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
