Commit 84b233ad authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: implement current_is_async() 



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: default avatarTejun Heo <tj@kernel.org>
parent 2eaebdb3

include/linux/async.h

+1 −0
Original line number Diff line number Diff line
@@ -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

kernel/async.c

+14 −0
Original line number Diff line number Diff line
@@ -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;

}

kernel/workqueue_internal.h

+11 −0
Original line number Diff line number Diff line
@@ -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.