diff options
Diffstat (limited to 'kernel/perf_counter.c')
-rw-r--r-- | kernel/perf_counter.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index bf12df6f353..2d4aebb2982 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -1917,6 +1917,99 @@ static void perf_counter_output(struct perf_counter *counter, } /* + * comm tracking + */ + +struct perf_comm_event { + struct task_struct *task; + char *comm; + int comm_size; + + struct { + struct perf_event_header header; + + u32 pid; + u32 tid; + } event; +}; + +static void perf_counter_comm_output(struct perf_counter *counter, + struct perf_comm_event *comm_event) +{ + struct perf_output_handle handle; + int size = comm_event->event.header.size; + int ret = perf_output_begin(&handle, counter, size, 0, 0); + + if (ret) + return; + + perf_output_put(&handle, comm_event->event); + perf_output_copy(&handle, comm_event->comm, + comm_event->comm_size); + perf_output_end(&handle); +} + +static int perf_counter_comm_match(struct perf_counter *counter, + struct perf_comm_event *comm_event) +{ + if (counter->hw_event.comm && + comm_event->event.header.type == PERF_EVENT_COMM) + return 1; + + return 0; +} + +static void perf_counter_comm_ctx(struct perf_counter_context *ctx, + struct perf_comm_event *comm_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_comm_match(counter, comm_event)) + perf_counter_comm_output(counter, comm_event); + } + rcu_read_unlock(); +} + +static void perf_counter_comm_event(struct perf_comm_event *comm_event) +{ + struct perf_cpu_context *cpuctx; + unsigned int size; + char *comm = comm_event->task->comm; + + size = ALIGN(strlen(comm), sizeof(u64)); + + comm_event->comm = comm; + comm_event->comm_size = size; + + comm_event->event.header.size = sizeof(comm_event->event) + size; + + cpuctx = &get_cpu_var(perf_cpu_context); + perf_counter_comm_ctx(&cpuctx->ctx, comm_event); + put_cpu_var(perf_cpu_context); + + perf_counter_comm_ctx(¤t->perf_counter_ctx, comm_event); +} + +void perf_counter_comm(struct task_struct *task) +{ + struct perf_comm_event comm_event = { + .task = task, + .event = { + .header = { .type = PERF_EVENT_COMM, }, + .pid = task->group_leader->pid, + .tid = task->pid, + }, + }; + + perf_counter_comm_event(&comm_event); +} + +/* * mmap tracking */ |