Re: workqueue destruction BUG_ON

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2010-08-24 at 15:07 +0200, Tejun Heo wrote:

> > [  500.874185] ------------[ cut here ]------------
> > [  500.875212] kernel BUG at kernel/workqueue.c:2849!
> 
> Are you sure you're running the patched kernel?  With the patch
> applied, the BUG_ON() wouldn't be on line 2849 (on both rc1 and 2).

Yes:

void destroy_workqueue(struct workqueue_struct *wq)
{
        unsigned int cpu;
   
        wq->flags |= WQ_DYING;
        flush_workqueue(wq);
  
        /*
         * wq list is used to freeze wq, remove from list after
         * flushing is complete in case freeze races us.
         */
        spin_lock(&workqueue_lock);
        list_del(&wq->list);
        spin_unlock(&workqueue_lock);

        /* sanity check */
        for_each_cwq_cpu(cpu, wq) {
                struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
                int i;

                for (i = 0; i < WORK_NR_COLORS; i++)
                        BUG_ON(cwq->nr_in_flight[i]);
2849:           BUG_ON(cwq->nr_active);
                BUG_ON(!list_empty(&cwq->delayed_works));


Applying the patch reported some offset, but the kernel is just rc1 +
wireless stuff.

johannes