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

@@ -764,6 +764,11 @@ static int work_next_color(int color) · 763 unmodified lines
764	764	return (color + 1) % WORK_NR_COLORS;
765	765	}
766	766
	767	+static unsigned long pool_offq_flags(struct worker_pool *pool)
	768	+{
	769	+ return (pool->flags & POOL_BH) ? WORK_OFFQ_BH : 0;
	770	+}
	771	+
767	772	/*
768	773	* While queued, %WORK_STRUCT_PWQ is set and non flag bits of a work's data
769	774	* contain the pointer to the queued pwq. Once execution starts, the flag
@@ -2122,7 +2127,8 @@ static int try_to_grab_pending(struct work_struct *work, u32 cflags, · 1352 unmodified lines
2122	2127	* this destroys work->data needed by the next step, stash it.
2123	2128	*/
2124	2129	work_data = *work_data_bits(work);
2125		− set_work_pool_and_keep_pending(work, pool->id, 0);
	2130	+ set_work_pool_and_keep_pending(work, pool->id,
	2131	+ pool_offq_flags(pool));
2126	2132
2127	2133	/* must be the last step, see the function comment */
2128	2134	pwq_dec_nr_in_flight(pwq, work_data);
@@ -3175,7 +3181,7 @@ __acquires(&pool->lock) · 1046 unmodified lines
3175	3181	* PENDING and queued state changes happen together while IRQ is
3176	3182	* disabled.
3177	3183	*/
3178		− set_work_pool_and_clear_pending(work, pool->id, 0);
	3184	+ set_work_pool_and_clear_pending(work, pool->id, pool_offq_flags(pool));
3179	3185
3180	3186	pwq->stats[PWQ_STAT_STARTED]++;
3181	3187	raw_spin_unlock_irq(&pool->lock);