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-rw-r--r--kernel/workqueue.c79
1 files changed, 54 insertions, 25 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index d1d460bb9b02..017044c26233 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -48,6 +48,7 @@
#include <linux/moduleparam.h>
#include <linux/uaccess.h>
#include <linux/sched/isolation.h>
+#include <linux/nmi.h>
#include "workqueue_internal.h"
@@ -2135,7 +2136,7 @@ __acquires(&pool->lock)
* stop_machine. At the same time, report a quiescent RCU state so
* the same condition doesn't freeze RCU.
*/
- cond_resched_rcu_qs();
+ cond_resched();
spin_lock_irq(&pool->lock);
@@ -3940,6 +3941,37 @@ static int wq_clamp_max_active(int max_active, unsigned int flags,
return clamp_val(max_active, 1, lim);
}
+/*
+ * Workqueues which may be used during memory reclaim should have a rescuer
+ * to guarantee forward progress.
+ */
+static int init_rescuer(struct workqueue_struct *wq)
+{
+ struct worker *rescuer;
+ int ret;
+
+ if (!(wq->flags & WQ_MEM_RECLAIM))
+ return 0;
+
+ rescuer = alloc_worker(NUMA_NO_NODE);
+ if (!rescuer)
+ return -ENOMEM;
+
+ rescuer->rescue_wq = wq;
+ rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", wq->name);
+ ret = PTR_ERR_OR_ZERO(rescuer->task);
+ if (ret) {
+ kfree(rescuer);
+ return ret;
+ }
+
+ wq->rescuer = rescuer;
+ kthread_bind_mask(rescuer->task, cpu_possible_mask);
+ wake_up_process(rescuer->task);
+
+ return 0;
+}
+
struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
unsigned int flags,
int max_active,
@@ -4002,29 +4034,8 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt,
if (alloc_and_link_pwqs(wq) < 0)
goto err_free_wq;
- /*
- * Workqueues which may be used during memory reclaim should
- * have a rescuer to guarantee forward progress.
- */
- if (flags & WQ_MEM_RECLAIM) {
- struct worker *rescuer;
-
- rescuer = alloc_worker(NUMA_NO_NODE);
- if (!rescuer)
- goto err_destroy;
-
- rescuer->rescue_wq = wq;
- rescuer->task = kthread_create(rescuer_thread, rescuer, "%s",
- wq->name);
- if (IS_ERR(rescuer->task)) {
- kfree(rescuer);
- goto err_destroy;
- }
-
- wq->rescuer = rescuer;
- kthread_bind_mask(rescuer->task, cpu_possible_mask);
- wake_up_process(rescuer->task);
- }
+ if (wq_online && init_rescuer(wq) < 0)
+ goto err_destroy;
if ((wq->flags & WQ_SYSFS) && workqueue_sysfs_register(wq))
goto err_destroy;
@@ -4464,6 +4475,12 @@ void show_workqueue_state(void)
if (pwq->nr_active || !list_empty(&pwq->delayed_works))
show_pwq(pwq);
spin_unlock_irqrestore(&pwq->pool->lock, flags);
+ /*
+ * We could be printing a lot from atomic context, e.g.
+ * sysrq-t -> show_workqueue_state(). Avoid triggering
+ * hard lockup.
+ */
+ touch_nmi_watchdog();
}
}
@@ -4491,6 +4508,12 @@ void show_workqueue_state(void)
pr_cont("\n");
next_pool:
spin_unlock_irqrestore(&pool->lock, flags);
+ /*
+ * We could be printing a lot from atomic context, e.g.
+ * sysrq-t -> show_workqueue_state(). Avoid triggering
+ * hard lockup.
+ */
+ touch_nmi_watchdog();
}
rcu_read_unlock_sched();
@@ -5630,6 +5653,8 @@ int __init workqueue_init(void)
* archs such as power and arm64. As per-cpu pools created
* previously could be missing node hint and unbound pools NUMA
* affinity, fix them up.
+ *
+ * Also, while iterating workqueues, create rescuers if requested.
*/
wq_numa_init();
@@ -5641,8 +5666,12 @@ int __init workqueue_init(void)
}
}
- list_for_each_entry(wq, &workqueues, list)
+ list_for_each_entry(wq, &workqueues, list) {
wq_update_unbound_numa(wq, smp_processor_id(), true);
+ WARN(init_rescuer(wq),
+ "workqueue: failed to create early rescuer for %s",
+ wq->name);
+ }
mutex_unlock(&wq_pool_mutex);