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-rw-r--r--include/linux/lockdep.h18
-rw-r--r--kernel/timer.c4
-rw-r--r--kernel/trace/Makefile1
-rw-r--r--kernel/trace/trace_workqueue.c300
-rw-r--r--kernel/workqueue.c21
5 files changed, 38 insertions, 306 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index d36619ead3b..00e46376e28 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -157,6 +157,24 @@ struct lockdep_map {
#endif
};
+static inline void lockdep_copy_map(struct lockdep_map *to,
+ struct lockdep_map *from)
+{
+ int i;
+
+ *to = *from;
+ /*
+ * Since the class cache can be modified concurrently we could observe
+ * half pointers (64bit arch using 32bit copy insns). Therefore clear
+ * the caches and take the performance hit.
+ *
+ * XXX it doesn't work well with lockdep_set_class_and_subclass(), since
+ * that relies on cache abuse.
+ */
+ for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
+ to->class_cache[i] = NULL;
+}
+
/*
* Every lock has a list of other locks that were taken after it.
* We only grow the list, never remove from it:
diff --git a/kernel/timer.c b/kernel/timer.c
index 837c552fe83..09de9a941cd 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1108,7 +1108,9 @@ static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
* warnings as well as problems when looking into
* timer->lockdep_map, make a copy and use that here.
*/
- struct lockdep_map lockdep_map = timer->lockdep_map;
+ struct lockdep_map lockdep_map;
+
+ lockdep_copy_map(&lockdep_map, &timer->lockdep_map);
#endif
/*
* Couple the lock chain with the lock chain at
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 5f39a07fe5e..b3afe0e76f7 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -41,7 +41,6 @@ obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
-obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
ifeq ($(CONFIG_BLOCK),y)
obj-$(CONFIG_EVENT_TRACING) += blktrace.o
diff --git a/kernel/trace/trace_workqueue.c b/kernel/trace/trace_workqueue.c
deleted file mode 100644
index 209b379a472..00000000000
--- a/kernel/trace/trace_workqueue.c
+++ /dev/null
@@ -1,300 +0,0 @@
-/*
- * Workqueue statistical tracer.
- *
- * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
- *
- */
-
-
-#include <trace/events/workqueue.h>
-#include <linux/list.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/kref.h>
-#include "trace_stat.h"
-#include "trace.h"
-
-
-/* A cpu workqueue thread */
-struct cpu_workqueue_stats {
- struct list_head list;
- struct kref kref;
- int cpu;
- pid_t pid;
-/* Can be inserted from interrupt or user context, need to be atomic */
- atomic_t inserted;
-/*
- * Don't need to be atomic, works are serialized in a single workqueue thread
- * on a single CPU.
- */
- unsigned int executed;
-};
-
-/* List of workqueue threads on one cpu */
-struct workqueue_global_stats {
- struct list_head list;
- spinlock_t lock;
-};
-
-/* Don't need a global lock because allocated before the workqueues, and
- * never freed.
- */
-static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);
-#define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))
-
-static void cpu_workqueue_stat_free(struct kref *kref)
-{
- kfree(container_of(kref, struct cpu_workqueue_stats, kref));
-}
-
-/* Insertion of a work */
-static void
-probe_workqueue_insertion(void *ignore,
- struct task_struct *wq_thread,
- struct work_struct *work)
-{
- int cpu = cpumask_first(&wq_thread->cpus_allowed);
- struct cpu_workqueue_stats *node;
- unsigned long flags;
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- list_for_each_entry(node, &workqueue_cpu_stat(cpu)->list, list) {
- if (node->pid == wq_thread->pid) {
- atomic_inc(&node->inserted);
- goto found;
- }
- }
- pr_debug("trace_workqueue: entry not found\n");
-found:
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-}
-
-/* Execution of a work */
-static void
-probe_workqueue_execution(void *ignore,
- struct task_struct *wq_thread,
- struct work_struct *work)
-{
- int cpu = cpumask_first(&wq_thread->cpus_allowed);
- struct cpu_workqueue_stats *node;
- unsigned long flags;
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- list_for_each_entry(node, &workqueue_cpu_stat(cpu)->list, list) {
- if (node->pid == wq_thread->pid) {
- node->executed++;
- goto found;
- }
- }
- pr_debug("trace_workqueue: entry not found\n");
-found:
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-}
-
-/* Creation of a cpu workqueue thread */
-static void probe_workqueue_creation(void *ignore,
- struct task_struct *wq_thread, int cpu)
-{
- struct cpu_workqueue_stats *cws;
- unsigned long flags;
-
- WARN_ON(cpu < 0);
-
- /* Workqueues are sometimes created in atomic context */
- cws = kzalloc(sizeof(struct cpu_workqueue_stats), GFP_ATOMIC);
- if (!cws) {
- pr_warning("trace_workqueue: not enough memory\n");
- return;
- }
- INIT_LIST_HEAD(&cws->list);
- kref_init(&cws->kref);
- cws->cpu = cpu;
- cws->pid = wq_thread->pid;
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- list_add_tail(&cws->list, &workqueue_cpu_stat(cpu)->list);
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-}
-
-/* Destruction of a cpu workqueue thread */
-static void
-probe_workqueue_destruction(void *ignore, struct task_struct *wq_thread)
-{
- /* Workqueue only execute on one cpu */
- int cpu = cpumask_first(&wq_thread->cpus_allowed);
- struct cpu_workqueue_stats *node, *next;
- unsigned long flags;
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- list_for_each_entry_safe(node, next, &workqueue_cpu_stat(cpu)->list,
- list) {
- if (node->pid == wq_thread->pid) {
- list_del(&node->list);
- kref_put(&node->kref, cpu_workqueue_stat_free);
- goto found;
- }
- }
-
- pr_debug("trace_workqueue: don't find workqueue to destroy\n");
-found:
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-
-}
-
-static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu)
-{
- unsigned long flags;
- struct cpu_workqueue_stats *ret = NULL;
-
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
-
- if (!list_empty(&workqueue_cpu_stat(cpu)->list)) {
- ret = list_entry(workqueue_cpu_stat(cpu)->list.next,
- struct cpu_workqueue_stats, list);
- kref_get(&ret->kref);
- }
-
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-
- return ret;
-}
-
-static void *workqueue_stat_start(struct tracer_stat *trace)
-{
- int cpu;
- void *ret = NULL;
-
- for_each_possible_cpu(cpu) {
- ret = workqueue_stat_start_cpu(cpu);
- if (ret)
- return ret;
- }
- return NULL;
-}
-
-static void *workqueue_stat_next(void *prev, int idx)
-{
- struct cpu_workqueue_stats *prev_cws = prev;
- struct cpu_workqueue_stats *ret;
- int cpu = prev_cws->cpu;
- unsigned long flags;
-
- spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
- if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
- do {
- cpu = cpumask_next(cpu, cpu_possible_mask);
- if (cpu >= nr_cpu_ids)
- return NULL;
- } while (!(ret = workqueue_stat_start_cpu(cpu)));
- return ret;
- } else {
- ret = list_entry(prev_cws->list.next,
- struct cpu_workqueue_stats, list);
- kref_get(&ret->kref);
- }
- spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
-
- return ret;
-}
-
-static int workqueue_stat_show(struct seq_file *s, void *p)
-{
- struct cpu_workqueue_stats *cws = p;
- struct pid *pid;
- struct task_struct *tsk;
-
- pid = find_get_pid(cws->pid);
- if (pid) {
- tsk = get_pid_task(pid, PIDTYPE_PID);
- if (tsk) {
- seq_printf(s, "%3d %6d %6u %s\n", cws->cpu,
- atomic_read(&cws->inserted), cws->executed,
- tsk->comm);
- put_task_struct(tsk);
- }
- put_pid(pid);
- }
-
- return 0;
-}
-
-static void workqueue_stat_release(void *stat)
-{
- struct cpu_workqueue_stats *node = stat;
-
- kref_put(&node->kref, cpu_workqueue_stat_free);
-}
-
-static int workqueue_stat_headers(struct seq_file *s)
-{
- seq_printf(s, "# CPU INSERTED EXECUTED NAME\n");
- seq_printf(s, "# | | | |\n");
- return 0;
-}
-
-struct tracer_stat workqueue_stats __read_mostly = {
- .name = "workqueues",
- .stat_start = workqueue_stat_start,
- .stat_next = workqueue_stat_next,
- .stat_show = workqueue_stat_show,
- .stat_release = workqueue_stat_release,
- .stat_headers = workqueue_stat_headers
-};
-
-
-int __init stat_workqueue_init(void)
-{
- if (register_stat_tracer(&workqueue_stats)) {
- pr_warning("Unable to register workqueue stat tracer\n");
- return 1;
- }
-
- return 0;
-}
-fs_initcall(stat_workqueue_init);
-
-/*
- * Workqueues are created very early, just after pre-smp initcalls.
- * So we must register our tracepoints at this stage.
- */
-int __init trace_workqueue_early_init(void)
-{
- int ret, cpu;
-
- for_each_possible_cpu(cpu) {
- spin_lock_init(&workqueue_cpu_stat(cpu)->lock);
- INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);
- }
-
- ret = register_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
- if (ret)
- goto out;
-
- ret = register_trace_workqueue_execution(probe_workqueue_execution, NULL);
- if (ret)
- goto no_insertion;
-
- ret = register_trace_workqueue_creation(probe_workqueue_creation, NULL);
- if (ret)
- goto no_execution;
-
- ret = register_trace_workqueue_destruction(probe_workqueue_destruction, NULL);
- if (ret)
- goto no_creation;
-
- return 0;
-
-no_creation:
- unregister_trace_workqueue_creation(probe_workqueue_creation, NULL);
-no_execution:
- unregister_trace_workqueue_execution(probe_workqueue_execution, NULL);
-no_insertion:
- unregister_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
-out:
- pr_warning("trace_workqueue: unable to trace workqueues\n");
-
- return 1;
-}
-early_initcall(trace_workqueue_early_init);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5abf42f63c0..9a3128dc67d 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1032,7 +1032,10 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
cwq = get_cwq(gcwq->cpu, wq);
trace_workqueue_queue_work(cpu, cwq, work);
- BUG_ON(!list_empty(&work->entry));
+ if (WARN_ON(!list_empty(&work->entry))) {
+ spin_unlock_irqrestore(&gcwq->lock, flags);
+ return;
+ }
cwq->nr_in_flight[cwq->work_color]++;
work_flags = work_color_to_flags(cwq->work_color);
@@ -1210,8 +1213,13 @@ static void worker_enter_idle(struct worker *worker)
} else
wake_up_all(&gcwq->trustee_wait);
- /* sanity check nr_running */
- WARN_ON_ONCE(gcwq->nr_workers == gcwq->nr_idle &&
+ /*
+ * Sanity check nr_running. Because trustee releases gcwq->lock
+ * between setting %WORKER_ROGUE and zapping nr_running, the
+ * warning may trigger spuriously. Check iff trustee is idle.
+ */
+ WARN_ON_ONCE(gcwq->trustee_state == TRUSTEE_DONE &&
+ gcwq->nr_workers == gcwq->nr_idle &&
atomic_read(get_gcwq_nr_running(gcwq->cpu)));
}
@@ -1810,7 +1818,9 @@ __acquires(&gcwq->lock)
* lock freed" warnings as well as problems when looking into
* work->lockdep_map, make a copy and use that here.
*/
- struct lockdep_map lockdep_map = work->lockdep_map;
+ struct lockdep_map lockdep_map;
+
+ lockdep_copy_map(&lockdep_map, &work->lockdep_map);
#endif
/*
* A single work shouldn't be executed concurrently by
@@ -2506,6 +2516,9 @@ bool flush_work(struct work_struct *work)
{
struct wq_barrier barr;
+ lock_map_acquire(&work->lockdep_map);
+ lock_map_release(&work->lockdep_map);
+
if (start_flush_work(work, &barr, true)) {
wait_for_completion(&barr.done);
destroy_work_on_stack(&barr.work);
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-09 21:48:56 +0000