--- /dev/null
+/*
+ * Workqueue statistical tracer.
+ *
+ * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ */
+
+
+#include <trace/workqueue.h>
+#include <linux/list.h>
+#include <linux/percpu.h>
+#include "trace_stat.h"
+#include "trace.h"
+
+
+/* A cpu workqueue thread */
+struct cpu_workqueue_stats {
+ struct list_head list;
+/* Useful to know if we print the cpu headers */
+ bool first_entry;
+ 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))
+
+/* Insertion of a work */
+static void
+probe_workqueue_insertion(struct task_struct *wq_thread,
+ struct work_struct *work)
+{
+ 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) {
+ 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(struct task_struct *wq_thread,
+ struct work_struct *work)
+{
+ 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) {
+ 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(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);
+ cws->cpu = cpu;
+
+ cws->pid = wq_thread->pid;
+
+ spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
+ if (list_empty(&workqueue_cpu_stat(cpu)->list))
+ cws->first_entry = true;
+ 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(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);
+ kfree(node);
+ 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);
+
+ spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
+
+ return ret;
+}
+
+static void *workqueue_stat_start(void)
+{
+ 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;
+ int cpu = prev_cws->cpu;
+ unsigned long flags;
+ void *ret = NULL;
+
+ 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;
+ }
+ spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
+
+ return list_entry(prev_cws->list.next, struct cpu_workqueue_stats,
+ list);
+}
+
+static int workqueue_stat_show(struct seq_file *s, void *p)
+{
+ struct cpu_workqueue_stats *cws = p;
+ unsigned long flags;
+ int cpu = cws->cpu;
+ struct pid *pid;
+ struct task_struct *tsk;
+
+ spin_lock_irqsave(&workqueue_cpu_stat(cpu)->lock, flags);
+ if (&cws->list == workqueue_cpu_stat(cpu)->list.next)
+ seq_printf(s, "\n");
+ spin_unlock_irqrestore(&workqueue_cpu_stat(cpu)->lock, flags);
+
+ 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 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_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;
+
+ ret = register_trace_workqueue_insertion(probe_workqueue_insertion);
+ if (ret)
+ goto out;
+
+ ret = register_trace_workqueue_execution(probe_workqueue_execution);
+ if (ret)
+ goto no_insertion;
+
+ ret = register_trace_workqueue_creation(probe_workqueue_creation);
+ if (ret)
+ goto no_execution;
+
+ ret = register_trace_workqueue_destruction(probe_workqueue_destruction);
+ if (ret)
+ goto no_creation;
+
+ for_each_possible_cpu(cpu) {
+ spin_lock_init(&workqueue_cpu_stat(cpu)->lock);
+ INIT_LIST_HEAD(&workqueue_cpu_stat(cpu)->list);
+ }
+
+ return 0;
+
+no_creation:
+ unregister_trace_workqueue_creation(probe_workqueue_creation);
+no_execution:
+ unregister_trace_workqueue_execution(probe_workqueue_execution);
+no_insertion:
+ unregister_trace_workqueue_insertion(probe_workqueue_insertion);
+out:
+ pr_warning("trace_workqueue: unable to trace workqueues\n");
+
+ return 1;
+}
+early_initcall(trace_workqueue_early_init);
projects / linux-2.6-omap-h63xx.git / blobdiff