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-rw-r--r--kernel/workqueue.c44
1 files changed, 34 insertions, 10 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0b72e81..7f5d4be 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2817,6 +2817,19 @@ already_gone:
return false;
}
+static bool __flush_work(struct work_struct *work)
+{
+ struct wq_barrier barr;
+
+ if (start_flush_work(work, &barr)) {
+ wait_for_completion(&barr.done);
+ destroy_work_on_stack(&barr.work);
+ return true;
+ } else {
+ return false;
+ }
+}
+
/**
* flush_work - wait for a work to finish executing the last queueing instance
* @work: the work to flush
@@ -2830,18 +2843,10 @@ already_gone:
*/
bool flush_work(struct work_struct *work)
{
- struct wq_barrier barr;
-
lock_map_acquire(&work->lockdep_map);
lock_map_release(&work->lockdep_map);
- if (start_flush_work(work, &barr)) {
- wait_for_completion(&barr.done);
- destroy_work_on_stack(&barr.work);
- return true;
- } else {
- return false;
- }
+ return __flush_work(work);
}
EXPORT_SYMBOL_GPL(flush_work);
@@ -3411,6 +3416,12 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to,
{
to->nice = from->nice;
cpumask_copy(to->cpumask, from->cpumask);
+ /*
+ * Unlike hash and equality test, this function doesn't ignore
+ * ->no_numa as it is used for both pool and wq attrs. Instead,
+ * get_unbound_pool() explicitly clears ->no_numa after copying.
+ */
+ to->no_numa = from->no_numa;
}
/* hash value of the content of @attr */
@@ -3578,6 +3589,12 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs)
lockdep_set_subclass(&pool->lock, 1); /* see put_pwq() */
copy_workqueue_attrs(pool->attrs, attrs);
+ /*
+ * no_numa isn't a worker_pool attribute, always clear it. See
+ * 'struct workqueue_attrs' comments for detail.
+ */
+ pool->attrs->no_numa = false;
+
/* if cpumask is contained inside a NUMA node, we belong to that node */
if (wq_numa_enabled) {
for_each_node(node) {
@@ -4756,7 +4773,14 @@ long work_on_cpu(int cpu, long (*fn)(void *), void *arg)
INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
schedule_work_on(cpu, &wfc.work);
- flush_work(&wfc.work);
+
+ /*
+ * The work item is on-stack and can't lead to deadlock through
+ * flushing. Use __flush_work() to avoid spurious lockdep warnings
+ * when work_on_cpu()s are nested.
+ */
+ __flush_work(&wfc.work);
+
return wfc.ret;
}
EXPORT_SYMBOL_GPL(work_on_cpu);
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