workqueue: Remember whether a work item was on a BH workqueue

Add an off-queue flag, WORK_OFFQ_BH, that indicates whether the last workqueue the work item was on was a BH one. This will be used to test whether a work item is BH in cancel_sync path to implement atomic cancel_sync'ing for BH work items.

Tejun Heo committed 2 years ago

Commit 456a78e1 parent f09b10b2 files · +11 −3Browse files

Showing the changes to kernel/workqueue.c (1 of 2 files). Show all

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kernel/workqueue.c+8−2

 	return (color + 1) % WORK_NR_COLORS;
 }
+static unsigned long pool_offq_flags(struct worker_pool *pool)
+{
+	return (pool->flags & POOL_BH) ? WORK_OFFQ_BH : 0;
+}
 /*
  * While queued, %WORK_STRUCT_PWQ is set and non flag bits of a work's data
  * contain the pointer to the queued pwq.  Once execution starts, the flag
 		 * this destroys work->data needed by the next step, stash it.
 		 */
 		work_data = *work_data_bits(work);
-		set_work_pool_and_keep_pending(work, pool->id, 0);
+		set_work_pool_and_keep_pending(work, pool->id,
+					       pool_offq_flags(pool));
 		/* must be the last step, see the function comment */
 		pwq_dec_nr_in_flight(pwq, work_data);
 	 * PENDING and queued state changes happen together while IRQ is
 	 * disabled.
 	 */
-	set_work_pool_and_clear_pending(work, pool->id, 0);
+	set_work_pool_and_clear_pending(work, pool->id, pool_offq_flags(pool));
 	pwq->stats[PWQ_STAT_STARTED]++;
 	raw_spin_unlock_irq(&pool->lock);