raw_spin_unlock_irq(&ctx->lock);
}
+#define MAX_INTERRUPTS (~0ULL)
+
+static void perf_log_throttle(struct perf_event *event, int enable);
+
static int
event_sched_in(struct perf_event *event,
struct perf_cpu_context *cpuctx,
event->state = PERF_EVENT_STATE_ACTIVE;
event->oncpu = smp_processor_id();
+
+ /*
+ * Unthrottle events, since we scheduled we might have missed several
+ * ticks already, also for a heavily scheduling task there is little
+ * guarantee it'll get a tick in a timely manner.
+ */
+ if (unlikely(event->hw.interrupts == MAX_INTERRUPTS)) {
+ perf_log_throttle(event, 1);
+ event->hw.interrupts = 0;
+ }
+
/*
* The new state must be visible before we turn it on in the hardware:
*/
}
}
-#define MAX_INTERRUPTS (~0ULL)
-
-static void perf_log_throttle(struct perf_event *event, int enable);
-
static u64 perf_calculate_period(struct perf_event *event, u64 nsec, u64 count)
{
u64 frequency = event->attr.sample_freq;
return;
raw_spin_lock(&ctx->lock);
- update_context_time(ctx);
+ if (ctx->is_active)
+ update_context_time(ctx);
update_event_times(event);
+ if (event->state == PERF_EVENT_STATE_ACTIVE)
+ event->pmu->read(event);
raw_spin_unlock(&ctx->lock);
-
- event->pmu->read(event);
}
static inline u64 perf_event_count(struct perf_event *event)
* accessed from NMI. Use a temporary manual per cpu allocation
* until that gets sorted out.
*/
- size = sizeof(*entries) + sizeof(struct perf_callchain_entry *) *
- num_possible_cpus();
+ size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
entries = kzalloc(size, GFP_KERNEL);
if (!entries)
if (!task)
return ERR_PTR(-ESRCH);
- /*
- * Can't attach events to a dying task.
- */
- err = -ESRCH;
- if (task->flags & PF_EXITING)
- goto errout;
-
/* Reuse ptrace permission checks for now. */
err = -EACCES;
if (!ptrace_may_access(task, PTRACE_MODE_READ))
if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
- if (cpu < 0 || cpu >= nr_cpumask_bits)
- return ERR_PTR(-EINVAL);
-
/*
* We could be clever and allow to attach a event to an
* offline CPU and activate it when the CPU comes up, but
get_ctx(ctx);
- if (cmpxchg(&task->perf_event_ctxp[ctxn], NULL, ctx)) {
- /*
- * We raced with some other task; use
- * the context they set.
- */
+ err = 0;
+ mutex_lock(&task->perf_event_mutex);
+ /*
+ * If it has already passed perf_event_exit_task().
+ * we must see PF_EXITING, it takes this mutex too.
+ */
+ if (task->flags & PF_EXITING)
+ err = -ESRCH;
+ else if (task->perf_event_ctxp[ctxn])
+ err = -EAGAIN;
+ else
+ rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
+ mutex_unlock(&task->perf_event_mutex);
+
+ if (unlikely(err)) {
put_task_struct(task);
kfree(ctx);
- goto retry;
+
+ if (err == -EAGAIN)
+ goto retry;
+ goto errout;
}
}
}
EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
-void inline perf_swevent_put_recursion_context(int rctx)
+inline void perf_swevent_put_recursion_context(int rctx)
{
struct swevent_htable *swhash = &__get_cpu_var(swevent_htable);
goto out;
}
+static struct lock_class_key cpuctx_mutex;
+
int perf_pmu_register(struct pmu *pmu, char *name, int type)
{
int cpu, ret;
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
__perf_event_init_context(&cpuctx->ctx);
+ lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
cpuctx->ctx.type = cpu_context;
cpuctx->ctx.pmu = pmu;
cpuctx->jiffies_interval = 1;
struct hw_perf_event *hwc;
long err;
+ if ((unsigned)cpu >= nr_cpu_ids) {
+ if (!task || cpu != -1)
+ return ERR_PTR(-EINVAL);
+ }
+
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
return ERR_PTR(-ENOMEM);
if (!overflow_handler && parent_event)
overflow_handler = parent_event->overflow_handler;
-
+
event->overflow_handler = overflow_handler;
if (attr->disabled)
* scheduled, so we are now safe from rescheduling changing
* our context.
*/
- child_ctx = child->perf_event_ctxp[ctxn];
+ child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
task_ctx_sched_out(child_ctx, EVENT_ALL);
/*
unsigned long flags;
int ret = 0;
- child->perf_event_ctxp[ctxn] = NULL;
-
- mutex_init(&child->perf_event_mutex);
- INIT_LIST_HEAD(&child->perf_event_list);
-
if (likely(!parent->perf_event_ctxp[ctxn]))
return 0;
{
int ctxn, ret;
+ memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
+ mutex_init(&child->perf_event_mutex);
+ INIT_LIST_HEAD(&child->perf_event_list);
+
for_each_task_context_nr(ctxn) {
ret = perf_event_init_context(child, ctxn);
if (ret)