diff options
| author | Tejun Heo <tj@kernel.org> | 2019-09-23 11:08:58 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2019-10-04 10:23:01 -0700 |
| commit | c29eb85386880750130a01aabf288408a6614d65 (patch) | |
| tree | a1611859442a41355f2182432afb2bec93921d01 /kernel/workqueue.c | |
| parent | 30ae2fc0a75eb5f1a38bbee7355d8e3bc823a6e1 (diff) | |
workqueue: more destroy_workqueue() fixes
destroy_workqueue() warnings still, at a lower frequency, trigger
spuriously. The problem seems to be in-flight operations which
haven't reached put_pwq() yet.
* Make sanity check grab all the related locks so that it's
synchronized against operations which puts pwq at the end.
* Always print out the offending pwq.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Williams, Gerald S" <gerald.s.williams@intel.com>
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 45 |
1 files changed, 31 insertions, 14 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 7f7aa45dac37..4a3c30177b94 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -355,6 +355,7 @@ EXPORT_SYMBOL_GPL(system_freezable_power_efficient_wq); static int worker_thread(void *__worker); static void workqueue_sysfs_unregister(struct workqueue_struct *wq); +static void show_pwq(struct pool_workqueue *pwq); #define CREATE_TRACE_POINTS #include <trace/events/workqueue.h> @@ -4314,6 +4315,22 @@ err_destroy: } EXPORT_SYMBOL_GPL(alloc_workqueue); +static bool pwq_busy(struct pool_workqueue *pwq) +{ + int i; + + for (i = 0; i < WORK_NR_COLORS; i++) + if (pwq->nr_in_flight[i]) + return true; + + if ((pwq != pwq->wq->dfl_pwq) && (pwq->refcnt > 1)) + return true; + if (pwq->nr_active || !list_empty(&pwq->delayed_works)) + return true; + + return false; +} + /** * destroy_workqueue - safely terminate a workqueue * @wq: target workqueue @@ -4348,28 +4365,28 @@ void destroy_workqueue(struct workqueue_struct *wq) kfree(rescuer); } - /* sanity checks */ + /* + * Sanity checks - grab all the locks so that we wait for all + * in-flight operations which may do put_pwq(). + */ + mutex_lock(&wq_pool_mutex); mutex_lock(&wq->mutex); for_each_pwq(pwq, wq) { - int i; - - for (i = 0; i < WORK_NR_COLORS; i++) { - if (WARN_ON(pwq->nr_in_flight[i])) { - mutex_unlock(&wq->mutex); - show_workqueue_state(); - return; - } - } - - if (WARN_ON((pwq != wq->dfl_pwq) && (pwq->refcnt > 1)) || - WARN_ON(pwq->nr_active) || - WARN_ON(!list_empty(&pwq->delayed_works))) { + spin_lock_irq(&pwq->pool->lock); + if (WARN_ON(pwq_busy(pwq))) { + pr_warning("%s: %s has the following busy pwq (refcnt=%d)\n", + __func__, wq->name, pwq->refcnt); + show_pwq(pwq); + spin_unlock_irq(&pwq->pool->lock); mutex_unlock(&wq->mutex); + mutex_unlock(&wq_pool_mutex); show_workqueue_state(); return; } + spin_unlock_irq(&pwq->pool->lock); } mutex_unlock(&wq->mutex); + mutex_unlock(&wq_pool_mutex); /* * wq list is used to freeze wq, remove from list after |