Merge branch 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue changes from Tejun Heo: "Nothing exciting. Most are updates to debug stuff and related fixes. Two not-too-critical bugs are fixed - WARN_ON() triggering spurious during cpu offlining and unlikely lockdep related oops." * 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: lockdep: fix oops in processing workqueue workqueue: skip nr_running sanity check in worker_enter_idle() if trustee is active workqueue: Catch more locking problems with flush_work() workqueue: change BUG_ON() to WARN_ON() trace: Remove unused workqueue tracer
This commit is contained in:
Linus Torvalds
commit
c54894cd46
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@ -157,6 +157,24 @@ struct lockdep_map {
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#endif
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};
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static inline void lockdep_copy_map(struct lockdep_map *to,
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struct lockdep_map *from)
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{
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int i;
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*to = *from;
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/*
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* Since the class cache can be modified concurrently we could observe
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* half pointers (64bit arch using 32bit copy insns). Therefore clear
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* the caches and take the performance hit.
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*
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* XXX it doesn't work well with lockdep_set_class_and_subclass(), since
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* that relies on cache abuse.
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*/
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for (i = 0; i < NR_LOCKDEP_CACHING_CLASSES; i++)
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to->class_cache[i] = NULL;
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}
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/*
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* Every lock has a list of other locks that were taken after it.
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* We only grow the list, never remove from it:
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@ -1108,7 +1108,9 @@ static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
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* warnings as well as problems when looking into
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* timer->lockdep_map, make a copy and use that here.
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*/
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struct lockdep_map lockdep_map = timer->lockdep_map;
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struct lockdep_map lockdep_map;
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lockdep_copy_map(&lockdep_map, &timer->lockdep_map);
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#endif
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/*
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* Couple the lock chain with the lock chain at
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@ -41,7 +41,6 @@ obj-$(CONFIG_STACK_TRACER) += trace_stack.o
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obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
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obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
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obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
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obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
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obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
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ifeq ($(CONFIG_BLOCK),y)
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obj-$(CONFIG_EVENT_TRACING) += blktrace.o
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@ -1,300 +0,0 @@
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/*
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* Workqueue statistical tracer.
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*
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* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
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*
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*/
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#include <trace/events/workqueue.h>
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#include <linux/list.h>
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#include <linux/percpu.h>
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#include <linux/slab.h>
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#include <linux/kref.h>
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#include "trace_stat.h"
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#include "trace.h"
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/* A cpu workqueue thread */
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struct cpu_workqueue_stats {
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struct list_head list;
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struct kref kref;
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int cpu;
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pid_t pid;
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/* Can be inserted from interrupt or user context, need to be atomic */
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atomic_t inserted;
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/*
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* Don't need to be atomic, works are serialized in a single workqueue thread
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* on a single CPU.
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*/
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unsigned int executed;
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};
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/* List of workqueue threads on one cpu */
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struct workqueue_global_stats {
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struct list_head list;
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spinlock_t lock;
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};
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/* Don't need a global lock because allocated before the workqueues, and
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* never freed.
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*/
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static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat);
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#define workqueue_cpu_stat(cpu) (&per_cpu(all_workqueue_stat, cpu))
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static void cpu_workqueue_stat_free(struct kref *kref)
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{
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kfree(container_of(kref, struct cpu_workqueue_stats, kref));
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}
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/* Insertion of a work */
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static void
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probe_workqueue_insertion(void *ignore,
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struct task_struct *wq_thread,
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struct work_struct *work)
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{
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int cpu = cpumask_first(&wq_thread->cpus_allowed);
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struct cpu_workqueue_stats *node;
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unsigned long flags;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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list_for_each_entry(node, &workqueue_cpu_stat(cpu)->list, list) {
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if (node->pid == wq_thread->pid) {
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atomic_inc(&node->inserted);
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goto found;
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}
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}
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pr_debug("trace_workqueue: entry not found\n");
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found:
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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}
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/* Execution of a work */
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static void
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probe_workqueue_execution(void *ignore,
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struct task_struct *wq_thread,
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struct work_struct *work)
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{
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int cpu = cpumask_first(&wq_thread->cpus_allowed);
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struct cpu_workqueue_stats *node;
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unsigned long flags;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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list_for_each_entry(node, &workqueue_cpu_stat(cpu)->list, list) {
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if (node->pid == wq_thread->pid) {
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node->executed++;
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goto found;
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}
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}
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pr_debug("trace_workqueue: entry not found\n");
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found:
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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}
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/* Creation of a cpu workqueue thread */
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static void probe_workqueue_creation(void *ignore,
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struct task_struct *wq_thread, int cpu)
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{
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struct cpu_workqueue_stats *cws;
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unsigned long flags;
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WARN_ON(cpu < 0);
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/* Workqueues are sometimes created in atomic context */
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cws = kzalloc(sizeof(struct cpu_workqueue_stats), GFP_ATOMIC);
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if (!cws) {
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pr_warning("trace_workqueue: not enough memory\n");
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return;
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}
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INIT_LIST_HEAD(&cws->list);
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kref_init(&cws->kref);
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cws->cpu = cpu;
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cws->pid = wq_thread->pid;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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list_add_tail(&cws->list, &workqueue_cpu_stat(cpu)->list);
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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}
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/* Destruction of a cpu workqueue thread */
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static void
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probe_workqueue_destruction(void *ignore, struct task_struct *wq_thread)
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{
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/* Workqueue only execute on one cpu */
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int cpu = cpumask_first(&wq_thread->cpus_allowed);
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struct cpu_workqueue_stats *node, *next;
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unsigned long flags;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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list_for_each_entry_safe(node, next, &workqueue_cpu_stat(cpu)->list,
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list) {
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if (node->pid == wq_thread->pid) {
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list_del(&node->list);
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kref_put(&node->kref, cpu_workqueue_stat_free);
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goto found;
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}
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}
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pr_debug("trace_workqueue: don't find workqueue to destroy\n");
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found:
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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}
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static struct cpu_workqueue_stats *workqueue_stat_start_cpu(int cpu)
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{
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unsigned long flags;
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struct cpu_workqueue_stats *ret = NULL;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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if (!list_empty(&workqueue_cpu_stat(cpu)->list)) {
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ret = list_entry(workqueue_cpu_stat(cpu)->list.next,
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struct cpu_workqueue_stats, list);
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kref_get(&ret->kref);
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}
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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return ret;
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}
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static void *workqueue_stat_start(struct tracer_stat *trace)
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{
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int cpu;
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void *ret = NULL;
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for_each_possible_cpu(cpu) {
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ret = workqueue_stat_start_cpu(cpu);
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if (ret)
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return ret;
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}
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return NULL;
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}
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static void *workqueue_stat_next(void *prev, int idx)
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{
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struct cpu_workqueue_stats *prev_cws = prev;
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struct cpu_workqueue_stats *ret;
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int cpu = prev_cws->cpu;
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unsigned long flags;
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spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
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if (list_is_last(&prev_cws->list, &workqueue_cpu_stat(cpu)->list)) {
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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do {
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cpu = cpumask_next(cpu, cpu_possible_mask);
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if (cpu >= nr_cpu_ids)
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return NULL;
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} while (!(ret = workqueue_stat_start_cpu(cpu)));
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return ret;
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} else {
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ret = list_entry(prev_cws->list.next,
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struct cpu_workqueue_stats, list);
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kref_get(&ret->kref);
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}
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spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
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return ret;
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}
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static int workqueue_stat_show(struct seq_file *s, void *p)
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{
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struct cpu_workqueue_stats *cws = p;
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struct pid *pid;
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struct task_struct *tsk;
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pid = find_get_pid(cws->pid);
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if (pid) {
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tsk = get_pid_task(pid, PIDTYPE_PID);
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if (tsk) {
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seq_printf(s, "%3d %6d %6u %s\n", cws->cpu,
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atomic_read(&cws->inserted), cws->executed,
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tsk->comm);
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put_task_struct(tsk);
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}
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put_pid(pid);
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}
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return 0;
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}
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static void workqueue_stat_release(void *stat)
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{
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struct cpu_workqueue_stats *node = stat;
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kref_put(&node->kref, cpu_workqueue_stat_free);
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}
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static int workqueue_stat_headers(struct seq_file *s)
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{
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seq_printf(s, "# CPU INSERTED EXECUTED NAME\n");
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seq_printf(s, "# | | | |\n");
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return 0;
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}
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struct tracer_stat workqueue_stats __read_mostly = {
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.name = "workqueues",
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.stat_start = workqueue_stat_start,
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.stat_next = workqueue_stat_next,
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.stat_show = workqueue_stat_show,
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.stat_release = workqueue_stat_release,
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.stat_headers = workqueue_stat_headers
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};
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int __init stat_workqueue_init(void)
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{
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if (register_stat_tracer(&workqueue_stats)) {
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pr_warning("Unable to register workqueue stat tracer\n");
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return 1;
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}
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return 0;
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}
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fs_initcall(stat_workqueue_init);
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/*
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* Workqueues are created very early, just after pre-smp initcalls.
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* So we must register our tracepoints at this stage.
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*/
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int __init trace_workqueue_early_init(void)
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{
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int ret, cpu;
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for_each_possible_cpu(cpu) {
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spin_lock_init(&workqueue_cpu_stat(cpu)->lock);
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INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);
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}
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ret = register_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
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if (ret)
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goto out;
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ret = register_trace_workqueue_execution(probe_workqueue_execution, NULL);
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if (ret)
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goto no_insertion;
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ret = register_trace_workqueue_creation(probe_workqueue_creation, NULL);
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if (ret)
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goto no_execution;
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ret = register_trace_workqueue_destruction(probe_workqueue_destruction, NULL);
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if (ret)
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goto no_creation;
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return 0;
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no_creation:
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unregister_trace_workqueue_creation(probe_workqueue_creation, NULL);
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no_execution:
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unregister_trace_workqueue_execution(probe_workqueue_execution, NULL);
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no_insertion:
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unregister_trace_workqueue_insertion(probe_workqueue_insertion, NULL);
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out:
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pr_warning("trace_workqueue: unable to trace workqueues\n");
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return 1;
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}
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early_initcall(trace_workqueue_early_init);
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@ -1032,7 +1032,10 @@ static void __queue_work(unsigned int cpu, struct workqueue_struct *wq,
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cwq = get_cwq(gcwq->cpu, wq);
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trace_workqueue_queue_work(cpu, cwq, work);
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BUG_ON(!list_empty(&work->entry));
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if (WARN_ON(!list_empty(&work->entry))) {
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spin_unlock_irqrestore(&gcwq->lock, flags);
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return;
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}
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cwq->nr_in_flight[cwq->work_color]++;
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work_flags = work_color_to_flags(cwq->work_color);
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@ -1210,8 +1213,13 @@ static void worker_enter_idle(struct worker *worker)
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} else
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wake_up_all(&gcwq->trustee_wait);
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/* sanity check nr_running */
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WARN_ON_ONCE(gcwq->nr_workers == gcwq->nr_idle &&
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/*
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* Sanity check nr_running. Because trustee releases gcwq->lock
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* between setting %WORKER_ROGUE and zapping nr_running, the
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* warning may trigger spuriously. Check iff trustee is idle.
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*/
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WARN_ON_ONCE(gcwq->trustee_state == TRUSTEE_DONE &&
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gcwq->nr_workers == gcwq->nr_idle &&
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atomic_read(get_gcwq_nr_running(gcwq->cpu)));
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}
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@ -1810,7 +1818,9 @@ __acquires(&gcwq->lock)
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* lock freed" warnings as well as problems when looking into
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* work->lockdep_map, make a copy and use that here.
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*/
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struct lockdep_map lockdep_map = work->lockdep_map;
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struct lockdep_map lockdep_map;
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lockdep_copy_map(&lockdep_map, &work->lockdep_map);
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#endif
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/*
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* A single work shouldn't be executed concurrently by
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|
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@ -2506,6 +2516,9 @@ bool flush_work(struct work_struct *work)
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{
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struct wq_barrier barr;
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|
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lock_map_acquire(&work->lockdep_map);
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lock_map_release(&work->lockdep_map);
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if (start_flush_work(work, &barr, true)) {
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wait_for_completion(&barr.done);
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destroy_work_on_stack(&barr.work);
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|
|
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Reference in New Issue