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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-02 15:26:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-02 15:26:41 -0700
commit4075409c9fcbc4b7967f2e92d808acc0b441d92e (patch)
tree4fec2a14de197bd7a59dd9d115a69eb6b5efbdbf /kernel
parentbba7d682277c09373b56b0461b0abbd0b3d1e872 (diff)
parentf9eaaa82b474350aa8436d15a7ae150a3c8b9d5c (diff)
downloadlinux-4075409c9fcbc4b7967f2e92d808acc0b441d92e.tar.bz2
Merge branch 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo: "Nothing too interesting. An optimization to short-circuit noop cpumask updates, debug dump code reorg, and doc update" * 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: doc: Call out the non-reentrance conditions workqueue: Introduce show_one_worker_pool and show_one_workqueue. workqueue: make sysfs of unbound kworker cpumask more clever
Diffstat (limited to 'kernel')
-rw-r--r--kernel/power/process.c2
-rw-r--r--kernel/workqueue.c187
2 files changed, 108 insertions, 81 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 37401c99b7d7..b7e7798637b8 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -94,7 +94,7 @@ static int try_to_freeze_tasks(bool user_only)
todo - wq_busy, wq_busy);
if (wq_busy)
- show_workqueue_state();
+ show_all_workqueues();
if (!wakeup || pm_debug_messages_on) {
read_lock(&tasklist_lock);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1b3eb1e9531f..1a7df882f55e 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -375,6 +375,7 @@ 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);
+static void show_one_worker_pool(struct worker_pool *pool);
#define CREATE_TRACE_POINTS
#include <trace/events/workqueue.h>
@@ -4447,7 +4448,7 @@ void destroy_workqueue(struct workqueue_struct *wq)
raw_spin_unlock_irq(&pwq->pool->lock);
mutex_unlock(&wq->mutex);
mutex_unlock(&wq_pool_mutex);
- show_workqueue_state();
+ show_one_workqueue(wq);
return;
}
raw_spin_unlock_irq(&pwq->pool->lock);
@@ -4797,97 +4798,116 @@ static void show_pwq(struct pool_workqueue *pwq)
}
/**
- * show_workqueue_state - dump workqueue state
- *
- * Called from a sysrq handler or try_to_freeze_tasks() and prints out
- * all busy workqueues and pools.
+ * show_one_workqueue - dump state of specified workqueue
+ * @wq: workqueue whose state will be printed
*/
-void show_workqueue_state(void)
+void show_one_workqueue(struct workqueue_struct *wq)
{
- struct workqueue_struct *wq;
- struct worker_pool *pool;
+ struct pool_workqueue *pwq;
+ bool idle = true;
unsigned long flags;
- int pi;
-
- rcu_read_lock();
-
- pr_info("Showing busy workqueues and worker pools:\n");
-
- list_for_each_entry_rcu(wq, &workqueues, list) {
- struct pool_workqueue *pwq;
- bool idle = true;
- for_each_pwq(pwq, wq) {
- if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
- idle = false;
- break;
- }
+ for_each_pwq(pwq, wq) {
+ if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
+ idle = false;
+ break;
}
- if (idle)
- continue;
+ }
+ if (idle) /* Nothing to print for idle workqueue */
+ return;
- pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
+ pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
- for_each_pwq(pwq, wq) {
- raw_spin_lock_irqsave(&pwq->pool->lock, flags);
- if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
- /*
- * Defer printing to avoid deadlocks in console
- * drivers that queue work while holding locks
- * also taken in their write paths.
- */
- printk_deferred_enter();
- show_pwq(pwq);
- printk_deferred_exit();
- }
- raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
+ for_each_pwq(pwq, wq) {
+ raw_spin_lock_irqsave(&pwq->pool->lock, flags);
+ if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
/*
- * We could be printing a lot from atomic context, e.g.
- * sysrq-t -> show_workqueue_state(). Avoid triggering
- * hard lockup.
+ * Defer printing to avoid deadlocks in console
+ * drivers that queue work while holding locks
+ * also taken in their write paths.
*/
- touch_nmi_watchdog();
- }
- }
-
- for_each_pool(pool, pi) {
- struct worker *worker;
- bool first = true;
-
- raw_spin_lock_irqsave(&pool->lock, flags);
- if (pool->nr_workers == pool->nr_idle)
- goto next_pool;
- /*
- * Defer printing to avoid deadlocks in console drivers that
- * queue work while holding locks also taken in their write
- * paths.
- */
- printk_deferred_enter();
- pr_info("pool %d:", pool->id);
- pr_cont_pool_info(pool);
- pr_cont(" hung=%us workers=%d",
- jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000,
- pool->nr_workers);
- if (pool->manager)
- pr_cont(" manager: %d",
- task_pid_nr(pool->manager->task));
- list_for_each_entry(worker, &pool->idle_list, entry) {
- pr_cont(" %s%d", first ? "idle: " : "",
- task_pid_nr(worker->task));
- first = false;
+ printk_deferred_enter();
+ show_pwq(pwq);
+ printk_deferred_exit();
}
- pr_cont("\n");
- printk_deferred_exit();
- next_pool:
- raw_spin_unlock_irqrestore(&pool->lock, flags);
+ raw_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
+ * sysrq-t -> show_all_workqueues(). Avoid triggering
* hard lockup.
*/
touch_nmi_watchdog();
}
+}
+
+/**
+ * show_one_worker_pool - dump state of specified worker pool
+ * @pool: worker pool whose state will be printed
+ */
+static void show_one_worker_pool(struct worker_pool *pool)
+{
+ struct worker *worker;
+ bool first = true;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&pool->lock, flags);
+ if (pool->nr_workers == pool->nr_idle)
+ goto next_pool;
+ /*
+ * Defer printing to avoid deadlocks in console drivers that
+ * queue work while holding locks also taken in their write
+ * paths.
+ */
+ printk_deferred_enter();
+ pr_info("pool %d:", pool->id);
+ pr_cont_pool_info(pool);
+ pr_cont(" hung=%us workers=%d",
+ jiffies_to_msecs(jiffies - pool->watchdog_ts) / 1000,
+ pool->nr_workers);
+ if (pool->manager)
+ pr_cont(" manager: %d",
+ task_pid_nr(pool->manager->task));
+ list_for_each_entry(worker, &pool->idle_list, entry) {
+ pr_cont(" %s%d", first ? "idle: " : "",
+ task_pid_nr(worker->task));
+ first = false;
+ }
+ pr_cont("\n");
+ printk_deferred_exit();
+next_pool:
+ raw_spin_unlock_irqrestore(&pool->lock, flags);
+ /*
+ * We could be printing a lot from atomic context, e.g.
+ * sysrq-t -> show_all_workqueues(). Avoid triggering
+ * hard lockup.
+ */
+ touch_nmi_watchdog();
+
+}
+
+/**
+ * show_all_workqueues - dump workqueue state
+ *
+ * Called from a sysrq handler or try_to_freeze_tasks() and prints out
+ * all busy workqueues and pools.
+ */
+void show_all_workqueues(void)
+{
+ struct workqueue_struct *wq;
+ struct worker_pool *pool;
+ int pi;
+
+ rcu_read_lock();
+
+ pr_info("Showing busy workqueues and worker pools:\n");
+
+ list_for_each_entry_rcu(wq, &workqueues, list)
+ show_one_workqueue(wq);
+
+ for_each_pool(pool, pi)
+ show_one_worker_pool(pool);
+
rcu_read_unlock();
}
@@ -5384,9 +5404,6 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
int ret = -EINVAL;
cpumask_var_t saved_cpumask;
- if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL))
- return -ENOMEM;
-
/*
* Not excluding isolated cpus on purpose.
* If the user wishes to include them, we allow that.
@@ -5394,6 +5411,15 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
cpumask_and(cpumask, cpumask, cpu_possible_mask);
if (!cpumask_empty(cpumask)) {
apply_wqattrs_lock();
+ if (cpumask_equal(cpumask, wq_unbound_cpumask)) {
+ ret = 0;
+ goto out_unlock;
+ }
+
+ if (!zalloc_cpumask_var(&saved_cpumask, GFP_KERNEL)) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
/* save the old wq_unbound_cpumask. */
cpumask_copy(saved_cpumask, wq_unbound_cpumask);
@@ -5406,10 +5432,11 @@ int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
if (ret < 0)
cpumask_copy(wq_unbound_cpumask, saved_cpumask);
+ free_cpumask_var(saved_cpumask);
+out_unlock:
apply_wqattrs_unlock();
}
- free_cpumask_var(saved_cpumask);
return ret;
}
@@ -5869,7 +5896,7 @@ static void wq_watchdog_timer_fn(struct timer_list *unused)
rcu_read_unlock();
if (lockup_detected)
- show_workqueue_state();
+ show_all_workqueues();
wq_watchdog_reset_touched();
mod_timer(&wq_watchdog_timer, jiffies + thresh);