1 files changed, 47 insertions, 20 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 11869faa6819..0400553f0d04 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -79,7 +79,9 @@ enum {
         MAX_IDLE_WORKERS_RATIO  = 4,            /* 1/4 of busy can be idle */
         IDLE_WORKER_TIMEOUT     = 300 * HZ,     /* keep idle ones for 5 mins */
 
-        MAYDAY_INITIAL_TIMEOUT  = HZ / 100,     /* call for help after 10ms */
+        MAYDAY_INITIAL_TIMEOUT  = HZ / 100 >= 2 ? HZ / 100 : 2,
+                                                /* call for help after 10ms
+                                                   (min two ticks) */
         MAYDAY_INTERVAL         = HZ / 10,      /* and then every 100ms */
         CREATE_COOLDOWN         = HZ,           /* time to breath after fail */
         TRUSTEE_COOLDOWN        = HZ / 10,      /* for trustee draining */
@@ -249,10 +251,12 @@ struct workqueue_struct *system_wq __read_mostly;
 struct workqueue_struct *system_long_wq __read_mostly;
 struct workqueue_struct *system_nrt_wq __read_mostly;
 struct workqueue_struct *system_unbound_wq __read_mostly;
+struct workqueue_struct *system_freezable_wq __read_mostly;
 EXPORT_SYMBOL_GPL(system_wq);
 EXPORT_SYMBOL_GPL(system_long_wq);
 EXPORT_SYMBOL_GPL(system_nrt_wq);
 EXPORT_SYMBOL_GPL(system_unbound_wq);
+EXPORT_SYMBOL_GPL(system_freezable_wq);
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/workqueue.h>
@@ -314,6 +318,11 @@ static inline int __next_wq_cpu(int cpu, const struct cpumask *mask,
 
 static struct debug_obj_descr work_debug_descr;
 
+static void *work_debug_hint(void *addr)
+{
+        return ((struct work_struct *) addr)->func;
+}
+
 /*
  * fixup_init is called when:
  * - an active object is initialized
@@ -385,6 +394,7 @@ static int work_fixup_free(void *addr, enum debug_obj_state state)
 
 static struct debug_obj_descr work_debug_descr = {
         .name           = "work_struct",
+        .debug_hint     = work_debug_hint,
         .fixup_init     = work_fixup_init,
         .fixup_activate = work_fixup_activate,
         .fixup_free     = work_fixup_free,
@@ -1281,8 +1291,14 @@ __acquires(&gcwq->lock)
                         return true;
                 spin_unlock_irq(&gcwq->lock);
 
-                /* CPU has come up inbetween, retry migration */
+                /*
+                 * We've raced with CPU hot[un]plug.  Give it a breather
+                 * and retry migration.  cond_resched() is required here;
+                 * otherwise, we might deadlock against cpu_stop trying to
+                 * bring down the CPU on non-preemptive kernel.
+                 */
                 cpu_relax();
+                cond_resched();
         }
 }
 
@@ -1356,8 +1372,10 @@ static struct worker *create_worker(struct global_cwq *gcwq, bool bind)
         worker->id = id;
 
         if (!on_unbound_cpu)
-                worker->task = kthread_create(worker_thread, worker,
-                                              "kworker/%u:%d", gcwq->cpu, id);
+                worker->task = kthread_create_on_node(worker_thread,
+                                                      worker,
+                                                      cpu_to_node(gcwq->cpu),
+                                                      "kworker/%u:%d", gcwq->cpu, id);
         else
                 worker->task = kthread_create(worker_thread, worker,
                                               "kworker/u:%d", id);
@@ -2047,6 +2065,15 @@ repeat:
                                 move_linked_works(work, scheduled, &n);
 
                 process_scheduled_works(rescuer);
+
+                /*
+                 * Leave this gcwq.  If keep_working() is %true, notify a
+                 * regular worker; otherwise, we end up with 0 concurrency
+                 * and stalling the execution.
+                 */
+                if (keep_working(gcwq))
+                        wake_up_worker(gcwq);
+
                 spin_unlock_irq(&gcwq->lock);
         }
 
@@ -2839,9 +2866,7 @@ static int alloc_cwqs(struct workqueue_struct *wq)
                 }
         }
 
-        /* just in case, make sure it's actually aligned
-         * - this is affected by PERCPU() alignment in vmlinux.lds.S
-         */
+        /* just in case, make sure it's actually aligned */
         BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
         return wq->cpu_wq.v ? 0 : -ENOMEM;
 }
@@ -2956,7 +2981,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name,
          */
         spin_lock(&workqueue_lock);
 
-        if (workqueue_freezing && wq->flags & WQ_FREEZEABLE)
+        if (workqueue_freezing && wq->flags & WQ_FREEZABLE)
                 for_each_cwq_cpu(cpu, wq)
                         get_cwq(cpu, wq)->max_active = 0;
 
@@ -3068,7 +3093,7 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active)
 
                 spin_lock_irq(&gcwq->lock);
 
-                if (!(wq->flags & WQ_FREEZEABLE) ||
+                if (!(wq->flags & WQ_FREEZABLE) ||
                     !(gcwq->flags & GCWQ_FREEZING))
                         get_cwq(gcwq->cpu, wq)->max_active = max_active;
 
@@ -3318,7 +3343,7 @@ static int __cpuinit trustee_thread(void *__gcwq)
          * want to get it over with ASAP - spam rescuers, wake up as
          * many idlers as necessary and create new ones till the
          * worklist is empty.  Note that if the gcwq is frozen, there
-         * may be frozen works in freezeable cwqs.  Don't declare
+         * may be frozen works in freezable cwqs.  Don't declare
          * completion while frozen.
          */
         while (gcwq->nr_workers != gcwq->nr_idle ||
@@ -3576,9 +3601,9 @@ EXPORT_SYMBOL_GPL(work_on_cpu);
 /**
  * freeze_workqueues_begin - begin freezing workqueues
  *
- * Start freezing workqueues.  After this function returns, all
- * freezeable workqueues will queue new works to their frozen_works
- * list instead of gcwq->worklist.
+ * Start freezing workqueues.  After this function returns, all freezable
+ * workqueues will queue new works to their frozen_works list instead of
+ * gcwq->worklist.
  *
  * CONTEXT:
  * Grabs and releases workqueue_lock and gcwq->lock's.
@@ -3604,7 +3629,7 @@ void freeze_workqueues_begin(void)
                 list_for_each_entry(wq, &workqueues, list) {
                         struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
 
-                        if (cwq && wq->flags & WQ_FREEZEABLE)
+                        if (cwq && wq->flags & WQ_FREEZABLE)
                                 cwq->max_active = 0;
                 }
 
@@ -3615,7 +3640,7 @@ void freeze_workqueues_begin(void)
 }
 
 /**
- * freeze_workqueues_busy - are freezeable workqueues still busy?
+ * freeze_workqueues_busy - are freezable workqueues still busy?
  *
  * Check whether freezing is complete.  This function must be called
  * between freeze_workqueues_begin() and thaw_workqueues().
@@ -3624,8 +3649,8 @@ void freeze_workqueues_begin(void)
  * Grabs and releases workqueue_lock.
  *
  * RETURNS:
- * %true if some freezeable workqueues are still busy.  %false if
- * freezing is complete.
+ * %true if some freezable workqueues are still busy.  %false if freezing
+ * is complete.
  */
 bool freeze_workqueues_busy(void)
 {
@@ -3645,7 +3670,7 @@ bool freeze_workqueues_busy(void)
                 list_for_each_entry(wq, &workqueues, list) {
                         struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
 
-                        if (!cwq || !(wq->flags & WQ_FREEZEABLE))
+                        if (!cwq || !(wq->flags & WQ_FREEZABLE))
                                 continue;
 
                         BUG_ON(cwq->nr_active < 0);
@@ -3690,7 +3715,7 @@ void thaw_workqueues(void)
                 list_for_each_entry(wq, &workqueues, list) {
                         struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
 
-                        if (!cwq || !(wq->flags & WQ_FREEZEABLE))
+                        if (!cwq || !(wq->flags & WQ_FREEZABLE))
                                 continue;
 
                         /* restore max_active and repopulate worklist */
@@ -3764,8 +3789,10 @@ static int __init init_workqueues(void)
         system_nrt_wq = alloc_workqueue("events_nrt", WQ_NON_REENTRANT, 0);
         system_unbound_wq = alloc_workqueue("events_unbound", WQ_UNBOUND,
                                             WQ_UNBOUND_MAX_ACTIVE);
+        system_freezable_wq = alloc_workqueue("events_freezable",
+                                              WQ_FREEZABLE, 0);
         BUG_ON(!system_wq || !system_long_wq || !system_nrt_wq ||
-               !system_unbound_wq);
+               !system_unbound_wq || !system_freezable_wq);
         return 0;
 }
 early_initcall(init_workqueues);