+ group_entry.id = sub->id;
+ group_entry.counter = atomic64_read(&sub->count);
+
+ perf_output_put(&handle, group_entry);
+ }
+ }
+
+ if (sample_type & PERF_SAMPLE_CALLCHAIN) {
+ if (callchain)
+ perf_output_copy(&handle, callchain, callchain_size);
+ else {
+ u64 nr = 0;
+ perf_output_put(&handle, nr);
+ }
+ }
+
+ perf_output_end(&handle);
+}
+
+/*
+ * read event
+ */
+
+struct perf_read_event {
+ struct perf_event_header header;
+
+ u32 pid;
+ u32 tid;
+ u64 value;
+ u64 format[3];
+};
+
+static void
+perf_counter_read_event(struct perf_counter *counter,
+ struct task_struct *task)
+{
+ struct perf_output_handle handle;
+ struct perf_read_event event = {
+ .header = {
+ .type = PERF_EVENT_READ,
+ .misc = 0,
+ .size = sizeof(event) - sizeof(event.format),
+ },
+ .pid = perf_counter_pid(counter, task),
+ .tid = perf_counter_tid(counter, task),
+ .value = atomic64_read(&counter->count),
+ };
+ int ret, i = 0;
+
+ if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) {
+ event.header.size += sizeof(u64);
+ event.format[i++] = counter->total_time_enabled;
+ }
+
+ if (counter->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) {
+ event.header.size += sizeof(u64);
+ event.format[i++] = counter->total_time_running;
+ }
+
+ if (counter->attr.read_format & PERF_FORMAT_ID) {
+ u64 id;
+
+ event.header.size += sizeof(u64);
+ if (counter->parent)
+ id = counter->parent->id;
+ else
+ id = counter->id;
+
+ event.format[i++] = id;
+ }
+
+ ret = perf_output_begin(&handle, counter, event.header.size, 0, 0);
+ if (ret)
+ return;
+
+ perf_output_copy(&handle, &event, event.header.size);
+ perf_output_end(&handle);
+}
+
+/*
+ * fork tracking
+ */
+
+struct perf_fork_event {
+ struct task_struct *task;
+
+ struct {
+ struct perf_event_header header;
+
+ u32 pid;
+ u32 ppid;
+ } event;
+};
+
+static void perf_counter_fork_output(struct perf_counter *counter,
+ struct perf_fork_event *fork_event)
+{
+ struct perf_output_handle handle;
+ int size = fork_event->event.header.size;
+ struct task_struct *task = fork_event->task;
+ int ret = perf_output_begin(&handle, counter, size, 0, 0);
+
+ if (ret)
+ return;
+
+ fork_event->event.pid = perf_counter_pid(counter, task);
+ fork_event->event.ppid = perf_counter_pid(counter, task->real_parent);
+
+ perf_output_put(&handle, fork_event->event);
+ perf_output_end(&handle);
+}
+
+static int perf_counter_fork_match(struct perf_counter *counter)
+{
+ if (counter->attr.comm || counter->attr.mmap)
+ return 1;
+
+ return 0;
+}
+
+static void perf_counter_fork_ctx(struct perf_counter_context *ctx,
+ struct perf_fork_event *fork_event)
+{
+ struct perf_counter *counter;
+
+ if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+ return;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
+ if (perf_counter_fork_match(counter))
+ perf_counter_fork_output(counter, fork_event);
+ }
+ rcu_read_unlock();
+}
+
+static void perf_counter_fork_event(struct perf_fork_event *fork_event)
+{
+ struct perf_cpu_context *cpuctx;
+ struct perf_counter_context *ctx;
+
+ cpuctx = &get_cpu_var(perf_cpu_context);
+ perf_counter_fork_ctx(&cpuctx->ctx, fork_event);
+ put_cpu_var(perf_cpu_context);
+
+ rcu_read_lock();
+ /*
+ * doesn't really matter which of the child contexts the
+ * events ends up in.
+ */
+ ctx = rcu_dereference(current->perf_counter_ctxp);
+ if (ctx)
+ perf_counter_fork_ctx(ctx, fork_event);
+ rcu_read_unlock();
+}
+
+void perf_counter_fork(struct task_struct *task)
+{
+ struct perf_fork_event fork_event;