Merge branch 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo:
"Workqueue now prints debug information at the end of sysrq-t which
should be helpful when tracking down suspected workqueue stalls. It
only prints out the ones with something currently going on so it
shouldn't add much output in most cases"
* 'for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Reorder sysfs code
percpu: Fix trivial typos in comments
workqueue: dump workqueues on sysrq-t
workqueue: keep track of the flushing task and pool manager
workqueue: make the workqueues list RCU walkable
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 259a4d5..843f2cd 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -275,6 +275,7 @@
static void sysrq_handle_showstate(int key)
{
show_state();
+ show_workqueue_state();
}
static struct sysrq_key_op sysrq_showstate_op = {
.handler = sysrq_handle_showstate,
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index f597846..deee212 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -454,6 +454,7 @@
extern unsigned int work_busy(struct work_struct *work);
extern __printf(1, 2) void set_worker_desc(const char *fmt, ...);
extern void print_worker_info(const char *log_lvl, struct task_struct *task);
+extern void show_workqueue_state(void);
/**
* queue_work - queue work on a workqueue
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 41ff75b..586ad91 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -159,6 +159,7 @@
/* see manage_workers() for details on the two manager mutexes */
struct mutex manager_arb; /* manager arbitration */
+ struct worker *manager; /* L: purely informational */
struct mutex attach_mutex; /* attach/detach exclusion */
struct list_head workers; /* A: attached workers */
struct completion *detach_completion; /* all workers detached */
@@ -230,7 +231,7 @@
*/
struct workqueue_struct {
struct list_head pwqs; /* WR: all pwqs of this wq */
- struct list_head list; /* PL: list of all workqueues */
+ struct list_head list; /* PR: list of all workqueues */
struct mutex mutex; /* protects this wq */
int work_color; /* WQ: current work color */
@@ -257,6 +258,13 @@
#endif
char name[WQ_NAME_LEN]; /* I: workqueue name */
+ /*
+ * Destruction of workqueue_struct is sched-RCU protected to allow
+ * walking the workqueues list without grabbing wq_pool_mutex.
+ * This is used to dump all workqueues from sysrq.
+ */
+ struct rcu_head rcu;
+
/* hot fields used during command issue, aligned to cacheline */
unsigned int flags ____cacheline_aligned; /* WQ: WQ_* flags */
struct pool_workqueue __percpu *cpu_pwqs; /* I: per-cpu pwqs */
@@ -288,7 +296,7 @@
static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */
static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */
-static LIST_HEAD(workqueues); /* PL: list of all workqueues */
+static LIST_HEAD(workqueues); /* PR: list of all workqueues */
static bool workqueue_freezing; /* PL: have wqs started freezing? */
/* the per-cpu worker pools */
@@ -324,6 +332,7 @@
static int worker_thread(void *__worker);
static void copy_workqueue_attrs(struct workqueue_attrs *to,
const struct workqueue_attrs *from);
+static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
#define CREATE_TRACE_POINTS
#include <trace/events/workqueue.h>
@@ -1911,9 +1920,11 @@
*/
if (!mutex_trylock(&pool->manager_arb))
return false;
+ pool->manager = worker;
maybe_create_worker(pool);
+ pool->manager = NULL;
mutex_unlock(&pool->manager_arb);
return true;
}
@@ -2303,6 +2314,7 @@
struct wq_barrier {
struct work_struct work;
struct completion done;
+ struct task_struct *task; /* purely informational */
};
static void wq_barrier_func(struct work_struct *work)
@@ -2351,6 +2363,7 @@
INIT_WORK_ONSTACK(&barr->work, wq_barrier_func);
__set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work));
init_completion(&barr->done);
+ barr->task = current;
/*
* If @target is currently being executed, schedule the
@@ -2989,323 +3002,6 @@
}
EXPORT_SYMBOL_GPL(execute_in_process_context);
-#ifdef CONFIG_SYSFS
-/*
- * Workqueues with WQ_SYSFS flag set is visible to userland via
- * /sys/bus/workqueue/devices/WQ_NAME. All visible workqueues have the
- * following attributes.
- *
- * per_cpu RO bool : whether the workqueue is per-cpu or unbound
- * max_active RW int : maximum number of in-flight work items
- *
- * Unbound workqueues have the following extra attributes.
- *
- * id RO int : the associated pool ID
- * nice RW int : nice value of the workers
- * cpumask RW mask : bitmask of allowed CPUs for the workers
- */
-struct wq_device {
- struct workqueue_struct *wq;
- struct device dev;
-};
-
-static struct workqueue_struct *dev_to_wq(struct device *dev)
-{
- struct wq_device *wq_dev = container_of(dev, struct wq_device, dev);
-
- return wq_dev->wq;
-}
-
-static ssize_t per_cpu_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
-
- return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)!(wq->flags & WQ_UNBOUND));
-}
-static DEVICE_ATTR_RO(per_cpu);
-
-static ssize_t max_active_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
-
- return scnprintf(buf, PAGE_SIZE, "%d\n", wq->saved_max_active);
-}
-
-static ssize_t max_active_store(struct device *dev,
- struct device_attribute *attr, const char *buf,
- size_t count)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- int val;
-
- if (sscanf(buf, "%d", &val) != 1 || val <= 0)
- return -EINVAL;
-
- workqueue_set_max_active(wq, val);
- return count;
-}
-static DEVICE_ATTR_RW(max_active);
-
-static struct attribute *wq_sysfs_attrs[] = {
- &dev_attr_per_cpu.attr,
- &dev_attr_max_active.attr,
- NULL,
-};
-ATTRIBUTE_GROUPS(wq_sysfs);
-
-static ssize_t wq_pool_ids_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- const char *delim = "";
- int node, written = 0;
-
- rcu_read_lock_sched();
- for_each_node(node) {
- written += scnprintf(buf + written, PAGE_SIZE - written,
- "%s%d:%d", delim, node,
- unbound_pwq_by_node(wq, node)->pool->id);
- delim = " ";
- }
- written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
- rcu_read_unlock_sched();
-
- return written;
-}
-
-static ssize_t wq_nice_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- int written;
-
- mutex_lock(&wq->mutex);
- written = scnprintf(buf, PAGE_SIZE, "%d\n", wq->unbound_attrs->nice);
- mutex_unlock(&wq->mutex);
-
- return written;
-}
-
-/* prepare workqueue_attrs for sysfs store operations */
-static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct *wq)
-{
- struct workqueue_attrs *attrs;
-
- attrs = alloc_workqueue_attrs(GFP_KERNEL);
- if (!attrs)
- return NULL;
-
- mutex_lock(&wq->mutex);
- copy_workqueue_attrs(attrs, wq->unbound_attrs);
- mutex_unlock(&wq->mutex);
- return attrs;
-}
-
-static ssize_t wq_nice_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- struct workqueue_attrs *attrs;
- int ret;
-
- attrs = wq_sysfs_prep_attrs(wq);
- if (!attrs)
- return -ENOMEM;
-
- if (sscanf(buf, "%d", &attrs->nice) == 1 &&
- attrs->nice >= MIN_NICE && attrs->nice <= MAX_NICE)
- ret = apply_workqueue_attrs(wq, attrs);
- else
- ret = -EINVAL;
-
- free_workqueue_attrs(attrs);
- return ret ?: count;
-}
-
-static ssize_t wq_cpumask_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- int written;
-
- mutex_lock(&wq->mutex);
- written = scnprintf(buf, PAGE_SIZE, "%*pb\n",
- cpumask_pr_args(wq->unbound_attrs->cpumask));
- mutex_unlock(&wq->mutex);
- return written;
-}
-
-static ssize_t wq_cpumask_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- struct workqueue_attrs *attrs;
- int ret;
-
- attrs = wq_sysfs_prep_attrs(wq);
- if (!attrs)
- return -ENOMEM;
-
- ret = cpumask_parse(buf, attrs->cpumask);
- if (!ret)
- ret = apply_workqueue_attrs(wq, attrs);
-
- free_workqueue_attrs(attrs);
- return ret ?: count;
-}
-
-static ssize_t wq_numa_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- int written;
-
- mutex_lock(&wq->mutex);
- written = scnprintf(buf, PAGE_SIZE, "%d\n",
- !wq->unbound_attrs->no_numa);
- mutex_unlock(&wq->mutex);
-
- return written;
-}
-
-static ssize_t wq_numa_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct workqueue_struct *wq = dev_to_wq(dev);
- struct workqueue_attrs *attrs;
- int v, ret;
-
- attrs = wq_sysfs_prep_attrs(wq);
- if (!attrs)
- return -ENOMEM;
-
- ret = -EINVAL;
- if (sscanf(buf, "%d", &v) == 1) {
- attrs->no_numa = !v;
- ret = apply_workqueue_attrs(wq, attrs);
- }
-
- free_workqueue_attrs(attrs);
- return ret ?: count;
-}
-
-static struct device_attribute wq_sysfs_unbound_attrs[] = {
- __ATTR(pool_ids, 0444, wq_pool_ids_show, NULL),
- __ATTR(nice, 0644, wq_nice_show, wq_nice_store),
- __ATTR(cpumask, 0644, wq_cpumask_show, wq_cpumask_store),
- __ATTR(numa, 0644, wq_numa_show, wq_numa_store),
- __ATTR_NULL,
-};
-
-static struct bus_type wq_subsys = {
- .name = "workqueue",
- .dev_groups = wq_sysfs_groups,
-};
-
-static int __init wq_sysfs_init(void)
-{
- return subsys_virtual_register(&wq_subsys, NULL);
-}
-core_initcall(wq_sysfs_init);
-
-static void wq_device_release(struct device *dev)
-{
- struct wq_device *wq_dev = container_of(dev, struct wq_device, dev);
-
- kfree(wq_dev);
-}
-
-/**
- * workqueue_sysfs_register - make a workqueue visible in sysfs
- * @wq: the workqueue to register
- *
- * Expose @wq in sysfs under /sys/bus/workqueue/devices.
- * alloc_workqueue*() automatically calls this function if WQ_SYSFS is set
- * which is the preferred method.
- *
- * Workqueue user should use this function directly iff it wants to apply
- * workqueue_attrs before making the workqueue visible in sysfs; otherwise,
- * apply_workqueue_attrs() may race against userland updating the
- * attributes.
- *
- * Return: 0 on success, -errno on failure.
- */
-int workqueue_sysfs_register(struct workqueue_struct *wq)
-{
- struct wq_device *wq_dev;
- int ret;
-
- /*
- * Adjusting max_active or creating new pwqs by applyting
- * attributes breaks ordering guarantee. Disallow exposing ordered
- * workqueues.
- */
- if (WARN_ON(wq->flags & __WQ_ORDERED))
- return -EINVAL;
-
- wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL);
- if (!wq_dev)
- return -ENOMEM;
-
- wq_dev->wq = wq;
- wq_dev->dev.bus = &wq_subsys;
- wq_dev->dev.init_name = wq->name;
- wq_dev->dev.release = wq_device_release;
-
- /*
- * unbound_attrs are created separately. Suppress uevent until
- * everything is ready.
- */
- dev_set_uevent_suppress(&wq_dev->dev, true);
-
- ret = device_register(&wq_dev->dev);
- if (ret) {
- kfree(wq_dev);
- wq->wq_dev = NULL;
- return ret;
- }
-
- if (wq->flags & WQ_UNBOUND) {
- struct device_attribute *attr;
-
- for (attr = wq_sysfs_unbound_attrs; attr->attr.name; attr++) {
- ret = device_create_file(&wq_dev->dev, attr);
- if (ret) {
- device_unregister(&wq_dev->dev);
- wq->wq_dev = NULL;
- return ret;
- }
- }
- }
-
- dev_set_uevent_suppress(&wq_dev->dev, false);
- kobject_uevent(&wq_dev->dev.kobj, KOBJ_ADD);
- return 0;
-}
-
-/**
- * workqueue_sysfs_unregister - undo workqueue_sysfs_register()
- * @wq: the workqueue to unregister
- *
- * If @wq is registered to sysfs by workqueue_sysfs_register(), unregister.
- */
-static void workqueue_sysfs_unregister(struct workqueue_struct *wq)
-{
- struct wq_device *wq_dev = wq->wq_dev;
-
- if (!wq->wq_dev)
- return;
-
- wq->wq_dev = NULL;
- device_unregister(&wq_dev->dev);
-}
-#else /* CONFIG_SYSFS */
-static void workqueue_sysfs_unregister(struct workqueue_struct *wq) { }
-#endif /* CONFIG_SYSFS */
-
/**
* free_workqueue_attrs - free a workqueue_attrs
* @attrs: workqueue_attrs to free
@@ -3424,6 +3120,20 @@
return 0;
}
+static void rcu_free_wq(struct rcu_head *rcu)
+{
+ struct workqueue_struct *wq =
+ container_of(rcu, struct workqueue_struct, rcu);
+
+ if (!(wq->flags & WQ_UNBOUND))
+ free_percpu(wq->cpu_pwqs);
+ else
+ free_workqueue_attrs(wq->unbound_attrs);
+
+ kfree(wq->rescuer);
+ kfree(wq);
+}
+
static void rcu_free_pool(struct rcu_head *rcu)
{
struct worker_pool *pool = container_of(rcu, struct worker_pool, rcu);
@@ -3601,12 +3311,10 @@
/*
* If we're the last pwq going away, @wq is already dead and no one
- * is gonna access it anymore. Free it.
+ * is gonna access it anymore. Schedule RCU free.
*/
- if (is_last) {
- free_workqueue_attrs(wq->unbound_attrs);
- kfree(wq);
- }
+ if (is_last)
+ call_rcu_sched(&wq->rcu, rcu_free_wq);
}
/**
@@ -4143,7 +3851,7 @@
pwq_adjust_max_active(pwq);
mutex_unlock(&wq->mutex);
- list_add(&wq->list, &workqueues);
+ list_add_tail_rcu(&wq->list, &workqueues);
mutex_unlock(&wq_pool_mutex);
@@ -4199,24 +3907,20 @@
* flushing is complete in case freeze races us.
*/
mutex_lock(&wq_pool_mutex);
- list_del_init(&wq->list);
+ list_del_rcu(&wq->list);
mutex_unlock(&wq_pool_mutex);
workqueue_sysfs_unregister(wq);
- if (wq->rescuer) {
+ if (wq->rescuer)
kthread_stop(wq->rescuer->task);
- kfree(wq->rescuer);
- wq->rescuer = NULL;
- }
if (!(wq->flags & WQ_UNBOUND)) {
/*
* The base ref is never dropped on per-cpu pwqs. Directly
- * free the pwqs and wq.
+ * schedule RCU free.
*/
- free_percpu(wq->cpu_pwqs);
- kfree(wq);
+ call_rcu_sched(&wq->rcu, rcu_free_wq);
} else {
/*
* We're the sole accessor of @wq at this point. Directly
@@ -4437,6 +4141,166 @@
}
}
+static void pr_cont_pool_info(struct worker_pool *pool)
+{
+ pr_cont(" cpus=%*pbl", nr_cpumask_bits, pool->attrs->cpumask);
+ if (pool->node != NUMA_NO_NODE)
+ pr_cont(" node=%d", pool->node);
+ pr_cont(" flags=0x%x nice=%d", pool->flags, pool->attrs->nice);
+}
+
+static void pr_cont_work(bool comma, struct work_struct *work)
+{
+ if (work->func == wq_barrier_func) {
+ struct wq_barrier *barr;
+
+ barr = container_of(work, struct wq_barrier, work);
+
+ pr_cont("%s BAR(%d)", comma ? "," : "",
+ task_pid_nr(barr->task));
+ } else {
+ pr_cont("%s %pf", comma ? "," : "", work->func);
+ }
+}
+
+static void show_pwq(struct pool_workqueue *pwq)
+{
+ struct worker_pool *pool = pwq->pool;
+ struct work_struct *work;
+ struct worker *worker;
+ bool has_in_flight = false, has_pending = false;
+ int bkt;
+
+ pr_info(" pwq %d:", pool->id);
+ pr_cont_pool_info(pool);
+
+ pr_cont(" active=%d/%d%s\n", pwq->nr_active, pwq->max_active,
+ !list_empty(&pwq->mayday_node) ? " MAYDAY" : "");
+
+ hash_for_each(pool->busy_hash, bkt, worker, hentry) {
+ if (worker->current_pwq == pwq) {
+ has_in_flight = true;
+ break;
+ }
+ }
+ if (has_in_flight) {
+ bool comma = false;
+
+ pr_info(" in-flight:");
+ hash_for_each(pool->busy_hash, bkt, worker, hentry) {
+ if (worker->current_pwq != pwq)
+ continue;
+
+ pr_cont("%s %d%s:%pf", comma ? "," : "",
+ task_pid_nr(worker->task),
+ worker == pwq->wq->rescuer ? "(RESCUER)" : "",
+ worker->current_func);
+ list_for_each_entry(work, &worker->scheduled, entry)
+ pr_cont_work(false, work);
+ comma = true;
+ }
+ pr_cont("\n");
+ }
+
+ list_for_each_entry(work, &pool->worklist, entry) {
+ if (get_work_pwq(work) == pwq) {
+ has_pending = true;
+ break;
+ }
+ }
+ if (has_pending) {
+ bool comma = false;
+
+ pr_info(" pending:");
+ list_for_each_entry(work, &pool->worklist, entry) {
+ if (get_work_pwq(work) != pwq)
+ continue;
+
+ pr_cont_work(comma, work);
+ comma = !(*work_data_bits(work) & WORK_STRUCT_LINKED);
+ }
+ pr_cont("\n");
+ }
+
+ if (!list_empty(&pwq->delayed_works)) {
+ bool comma = false;
+
+ pr_info(" delayed:");
+ list_for_each_entry(work, &pwq->delayed_works, entry) {
+ pr_cont_work(comma, work);
+ comma = !(*work_data_bits(work) & WORK_STRUCT_LINKED);
+ }
+ pr_cont("\n");
+ }
+}
+
+/**
+ * show_workqueue_state - dump workqueue state
+ *
+ * Called from a sysrq handler and prints out all busy workqueues and
+ * pools.
+ */
+void show_workqueue_state(void)
+{
+ struct workqueue_struct *wq;
+ struct worker_pool *pool;
+ unsigned long flags;
+ int pi;
+
+ rcu_read_lock_sched();
+
+ 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->delayed_works)) {
+ idle = false;
+ break;
+ }
+ }
+ if (idle)
+ continue;
+
+ pr_info("workqueue %s: flags=0x%x\n", wq->name, wq->flags);
+
+ for_each_pwq(pwq, wq) {
+ spin_lock_irqsave(&pwq->pool->lock, flags);
+ if (pwq->nr_active || !list_empty(&pwq->delayed_works))
+ show_pwq(pwq);
+ spin_unlock_irqrestore(&pwq->pool->lock, flags);
+ }
+ }
+
+ for_each_pool(pool, pi) {
+ struct worker *worker;
+ bool first = true;
+
+ spin_lock_irqsave(&pool->lock, flags);
+ if (pool->nr_workers == pool->nr_idle)
+ goto next_pool;
+
+ pr_info("pool %d:", pool->id);
+ pr_cont_pool_info(pool);
+ pr_cont(" workers=%d", 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");
+ next_pool:
+ spin_unlock_irqrestore(&pool->lock, flags);
+ }
+
+ rcu_read_unlock_sched();
+}
+
/*
* CPU hotplug.
*
@@ -4834,6 +4698,323 @@
}
#endif /* CONFIG_FREEZER */
+#ifdef CONFIG_SYSFS
+/*
+ * Workqueues with WQ_SYSFS flag set is visible to userland via
+ * /sys/bus/workqueue/devices/WQ_NAME. All visible workqueues have the
+ * following attributes.
+ *
+ * per_cpu RO bool : whether the workqueue is per-cpu or unbound
+ * max_active RW int : maximum number of in-flight work items
+ *
+ * Unbound workqueues have the following extra attributes.
+ *
+ * id RO int : the associated pool ID
+ * nice RW int : nice value of the workers
+ * cpumask RW mask : bitmask of allowed CPUs for the workers
+ */
+struct wq_device {
+ struct workqueue_struct *wq;
+ struct device dev;
+};
+
+static struct workqueue_struct *dev_to_wq(struct device *dev)
+{
+ struct wq_device *wq_dev = container_of(dev, struct wq_device, dev);
+
+ return wq_dev->wq;
+}
+
+static ssize_t per_cpu_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)!(wq->flags & WQ_UNBOUND));
+}
+static DEVICE_ATTR_RO(per_cpu);
+
+static ssize_t max_active_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%d\n", wq->saved_max_active);
+}
+
+static ssize_t max_active_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ int val;
+
+ if (sscanf(buf, "%d", &val) != 1 || val <= 0)
+ return -EINVAL;
+
+ workqueue_set_max_active(wq, val);
+ return count;
+}
+static DEVICE_ATTR_RW(max_active);
+
+static struct attribute *wq_sysfs_attrs[] = {
+ &dev_attr_per_cpu.attr,
+ &dev_attr_max_active.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(wq_sysfs);
+
+static ssize_t wq_pool_ids_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ const char *delim = "";
+ int node, written = 0;
+
+ rcu_read_lock_sched();
+ for_each_node(node) {
+ written += scnprintf(buf + written, PAGE_SIZE - written,
+ "%s%d:%d", delim, node,
+ unbound_pwq_by_node(wq, node)->pool->id);
+ delim = " ";
+ }
+ written += scnprintf(buf + written, PAGE_SIZE - written, "\n");
+ rcu_read_unlock_sched();
+
+ return written;
+}
+
+static ssize_t wq_nice_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ int written;
+
+ mutex_lock(&wq->mutex);
+ written = scnprintf(buf, PAGE_SIZE, "%d\n", wq->unbound_attrs->nice);
+ mutex_unlock(&wq->mutex);
+
+ return written;
+}
+
+/* prepare workqueue_attrs for sysfs store operations */
+static struct workqueue_attrs *wq_sysfs_prep_attrs(struct workqueue_struct *wq)
+{
+ struct workqueue_attrs *attrs;
+
+ attrs = alloc_workqueue_attrs(GFP_KERNEL);
+ if (!attrs)
+ return NULL;
+
+ mutex_lock(&wq->mutex);
+ copy_workqueue_attrs(attrs, wq->unbound_attrs);
+ mutex_unlock(&wq->mutex);
+ return attrs;
+}
+
+static ssize_t wq_nice_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ struct workqueue_attrs *attrs;
+ int ret;
+
+ attrs = wq_sysfs_prep_attrs(wq);
+ if (!attrs)
+ return -ENOMEM;
+
+ if (sscanf(buf, "%d", &attrs->nice) == 1 &&
+ attrs->nice >= MIN_NICE && attrs->nice <= MAX_NICE)
+ ret = apply_workqueue_attrs(wq, attrs);
+ else
+ ret = -EINVAL;
+
+ free_workqueue_attrs(attrs);
+ return ret ?: count;
+}
+
+static ssize_t wq_cpumask_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ int written;
+
+ mutex_lock(&wq->mutex);
+ written = scnprintf(buf, PAGE_SIZE, "%*pb\n",
+ cpumask_pr_args(wq->unbound_attrs->cpumask));
+ mutex_unlock(&wq->mutex);
+ return written;
+}
+
+static ssize_t wq_cpumask_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ struct workqueue_attrs *attrs;
+ int ret;
+
+ attrs = wq_sysfs_prep_attrs(wq);
+ if (!attrs)
+ return -ENOMEM;
+
+ ret = cpumask_parse(buf, attrs->cpumask);
+ if (!ret)
+ ret = apply_workqueue_attrs(wq, attrs);
+
+ free_workqueue_attrs(attrs);
+ return ret ?: count;
+}
+
+static ssize_t wq_numa_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ int written;
+
+ mutex_lock(&wq->mutex);
+ written = scnprintf(buf, PAGE_SIZE, "%d\n",
+ !wq->unbound_attrs->no_numa);
+ mutex_unlock(&wq->mutex);
+
+ return written;
+}
+
+static ssize_t wq_numa_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct workqueue_struct *wq = dev_to_wq(dev);
+ struct workqueue_attrs *attrs;
+ int v, ret;
+
+ attrs = wq_sysfs_prep_attrs(wq);
+ if (!attrs)
+ return -ENOMEM;
+
+ ret = -EINVAL;
+ if (sscanf(buf, "%d", &v) == 1) {
+ attrs->no_numa = !v;
+ ret = apply_workqueue_attrs(wq, attrs);
+ }
+
+ free_workqueue_attrs(attrs);
+ return ret ?: count;
+}
+
+static struct device_attribute wq_sysfs_unbound_attrs[] = {
+ __ATTR(pool_ids, 0444, wq_pool_ids_show, NULL),
+ __ATTR(nice, 0644, wq_nice_show, wq_nice_store),
+ __ATTR(cpumask, 0644, wq_cpumask_show, wq_cpumask_store),
+ __ATTR(numa, 0644, wq_numa_show, wq_numa_store),
+ __ATTR_NULL,
+};
+
+static struct bus_type wq_subsys = {
+ .name = "workqueue",
+ .dev_groups = wq_sysfs_groups,
+};
+
+static int __init wq_sysfs_init(void)
+{
+ return subsys_virtual_register(&wq_subsys, NULL);
+}
+core_initcall(wq_sysfs_init);
+
+static void wq_device_release(struct device *dev)
+{
+ struct wq_device *wq_dev = container_of(dev, struct wq_device, dev);
+
+ kfree(wq_dev);
+}
+
+/**
+ * workqueue_sysfs_register - make a workqueue visible in sysfs
+ * @wq: the workqueue to register
+ *
+ * Expose @wq in sysfs under /sys/bus/workqueue/devices.
+ * alloc_workqueue*() automatically calls this function if WQ_SYSFS is set
+ * which is the preferred method.
+ *
+ * Workqueue user should use this function directly iff it wants to apply
+ * workqueue_attrs before making the workqueue visible in sysfs; otherwise,
+ * apply_workqueue_attrs() may race against userland updating the
+ * attributes.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
+int workqueue_sysfs_register(struct workqueue_struct *wq)
+{
+ struct wq_device *wq_dev;
+ int ret;
+
+ /*
+ * Adjusting max_active or creating new pwqs by applyting
+ * attributes breaks ordering guarantee. Disallow exposing ordered
+ * workqueues.
+ */
+ if (WARN_ON(wq->flags & __WQ_ORDERED))
+ return -EINVAL;
+
+ wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL);
+ if (!wq_dev)
+ return -ENOMEM;
+
+ wq_dev->wq = wq;
+ wq_dev->dev.bus = &wq_subsys;
+ wq_dev->dev.init_name = wq->name;
+ wq_dev->dev.release = wq_device_release;
+
+ /*
+ * unbound_attrs are created separately. Suppress uevent until
+ * everything is ready.
+ */
+ dev_set_uevent_suppress(&wq_dev->dev, true);
+
+ ret = device_register(&wq_dev->dev);
+ if (ret) {
+ kfree(wq_dev);
+ wq->wq_dev = NULL;
+ return ret;
+ }
+
+ if (wq->flags & WQ_UNBOUND) {
+ struct device_attribute *attr;
+
+ for (attr = wq_sysfs_unbound_attrs; attr->attr.name; attr++) {
+ ret = device_create_file(&wq_dev->dev, attr);
+ if (ret) {
+ device_unregister(&wq_dev->dev);
+ wq->wq_dev = NULL;
+ return ret;
+ }
+ }
+ }
+
+ dev_set_uevent_suppress(&wq_dev->dev, false);
+ kobject_uevent(&wq_dev->dev.kobj, KOBJ_ADD);
+ return 0;
+}
+
+/**
+ * workqueue_sysfs_unregister - undo workqueue_sysfs_register()
+ * @wq: the workqueue to unregister
+ *
+ * If @wq is registered to sysfs by workqueue_sysfs_register(), unregister.
+ */
+static void workqueue_sysfs_unregister(struct workqueue_struct *wq)
+{
+ struct wq_device *wq_dev = wq->wq_dev;
+
+ if (!wq->wq_dev)
+ return;
+
+ wq->wq_dev = NULL;
+ device_unregister(&wq_dev->dev);
+}
+#else /* CONFIG_SYSFS */
+static void workqueue_sysfs_unregister(struct workqueue_struct *wq) { }
+#endif /* CONFIG_SYSFS */
+
static void __init wq_numa_init(void)
{
cpumask_var_t *tbl;
diff --git a/mm/percpu.c b/mm/percpu.c
index 73c97a5..dfd0248 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1310,7 +1310,7 @@
* and, from the second one, the backing allocator (currently either vm or
* km) provides translation.
*
- * The addr can be tranlated simply without checking if it falls into the
+ * The addr can be translated simply without checking if it falls into the
* first chunk. But the current code reflects better how percpu allocator
* actually works, and the verification can discover both bugs in percpu
* allocator itself and per_cpu_ptr_to_phys() callers. So we keep current
@@ -1762,7 +1762,7 @@
* and other parameters considering needed percpu size, allocation
* atom size and distances between CPUs.
*
- * Groups are always mutliples of atom size and CPUs which are of
+ * Groups are always multiples of atom size and CPUs which are of
* LOCAL_DISTANCE both ways are grouped together and share space for
* units in the same group. The returned configuration is guaranteed
* to have CPUs on different nodes on different groups and >=75% usage