On Thu, 2008-07-03 at 22:04 +0800, Alan Stern wrote: > On Thu, 3 Jul 2008, Zhang Rui wrote: > > > This interface allows adding a job on a specific cpu. > > > > Although a work struct on a cpu will be scheduled to other cpu if the cpu dies, > > there is a recursion if a work task tries to offline the cpu it's > running on. > > we need to schedule the task to a specific cpu in this case. > > http://bugzilla.kernel.org/show_bug.cgi?id=10897 > > > > Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> > > Tested-by: Rus <harbour@xxxxxxxxxxx> > > --- > > include/linux/workqueue.h | 1 + > > kernel/workqueue.c | 38 > ++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 39 insertions(+) > > > > Index: linux-2.6/include/linux/workqueue.h > > =================================================================== > > --- linux-2.6.orig/include/linux/workqueue.h 2008-07-03 > 11:13:23.000000000 +0800 > > +++ linux-2.6/include/linux/workqueue.h 2008-07-03 > 11:13:25.000000000 +0800 > > @@ -188,6 +188,7 @@ > > extern void flush_scheduled_work(void); > > > > extern int schedule_work(struct work_struct *work); > > +extern int schedule_work_on(int cpu, struct work_struct *work); > > extern int schedule_delayed_work(struct delayed_work *work, > unsigned long delay); > > extern int schedule_delayed_work_on(int cpu, struct delayed_work > *work, > > unsigned long delay); > > Is there some reason you don't export queue_work_on? After all, > queue_delayed_work_on is exported. Both are okay. I didn't export it just because no one would use it currently. Please review the patch below. thanks, rui Subject: introduce new interface schedule_work_on This interface allows adding a job on a specific cpu. Although a work struct on a cpu will be scheduled to other cpu if the cpu dies, there is a recursion if a work task tries to offline the cpu it's running on. we need to schedule the task to a specific cpu in this case. http://bugzilla.kernel.org/show_bug.cgi?id=10897 Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> Tested-by: Rus <harbour@xxxxxxxxxxx> --- include/linux/workqueue.h | 3 +++ kernel/workqueue.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+) Index: linux-2.6/include/linux/workqueue.h =================================================================== --- linux-2.6.orig/include/linux/workqueue.h 2007-05-04 10:57:08.000000000 +0800 +++ linux-2.6/include/linux/workqueue.h 2008-07-04 10:03:21.000000000 +0800 @@ -179,6 +179,8 @@ extern void destroy_workqueue(struct workqueue_struct *wq); extern int queue_work(struct workqueue_struct *wq, struct work_struct *work); +extern int queue_work_on(int cpu, struct workqueue_struct *wq, + struct work_struct *work); extern int queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work, unsigned long delay); extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, @@ -188,6 +190,7 @@ extern void flush_scheduled_work(void); extern int schedule_work(struct work_struct *work); +extern int schedule_work_on(int cpu, struct work_struct *work); extern int schedule_delayed_work(struct delayed_work *work, unsigned long delay); extern int schedule_delayed_work_on(int cpu, struct delayed_work *work, unsigned long delay); Index: linux-2.6/kernel/workqueue.c =================================================================== --- linux-2.6.orig/kernel/workqueue.c 2007-05-04 10:57:08.000000000 +0800 +++ linux-2.6/kernel/workqueue.c 2008-07-04 10:05:01.000000000 +0800 @@ -175,6 +175,32 @@ } EXPORT_SYMBOL_GPL(queue_work); +/** + * queue_work_on - queue work on specific cpu + * @cpu: CPU number to execute work on + * @wq: workqueue to use + * @work: work to queue + * + * Returns 0 if @work was already on a queue, non-zero otherwise. + * + * We queue the work to a specific CPU + */ +int +queue_work_on(int cpu, struct workqueue_struct *wq, struct work_struct *work) +{ + int ret = 0; + + if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) { + BUG_ON(!list_empty(&work->entry)); + preempt_disable(); + __queue_work(wq_per_cpu(wq, cpu), work); + preempt_enable(); + ret = 1; + } + return ret; +} +EXPORT_SYMBOL_GPL(queue_work_on); + static void delayed_work_timer_fn(unsigned long __data) { struct delayed_work *dwork = (struct delayed_work *)__data; @@ -553,6 +579,19 @@ } EXPORT_SYMBOL(schedule_work); +/* + * schedule_work_on - put work task on a specific cpu + * @cpu: cpu to put the work task on + * @work: job to be done + * + * This puts a job on a specific cpu + */ +int schedule_work_on(int cpu, struct work_struct *work) +{ + return queue_work_on(cpu, keventd_wq, work); +} +EXPORT_SYMBOL(schedule_work_on); + /** * schedule_delayed_work - put work task in global workqueue after delay * @dwork: job to be done _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
