perf: Add per event clockid support

[deliverable/linux.git] / kernel / events / core.c

diff --git a/kernel/events/core.c b/kernel/events/core.c
index bb1a7c36e7941d38c542449c467862effc6a282f..c40c2cac2d8e3eaf8106d8746aa83bb72e5899e5 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -327,6 +327,11 @@ static inline u64 perf_clock(void)
        return local_clock();
 }
 
+static inline u64 perf_event_clock(struct perf_event *event)
+{
+       return event->clock();
+}
+
 static inline struct perf_cpu_context *
 __get_cpu_context(struct perf_event_context *ctx)
 {
@@ -4762,7 +4767,7 @@ static void __perf_event_header__init_id(struct perf_event_header *header,
        }
 
        if (sample_type & PERF_SAMPLE_TIME)
-               data->time = perf_clock();
+               data->time = perf_event_clock(event);
 
        if (sample_type & (PERF_SAMPLE_ID | PERF_SAMPLE_IDENTIFIER))
                data->id = primary_event_id(event);
@@ -5340,6 +5345,8 @@ static void perf_event_task_output(struct perf_event *event,
        task_event->event_id.tid = perf_event_tid(event, task);
        task_event->event_id.ptid = perf_event_tid(event, current);
 
+       task_event->event_id.time = perf_event_clock(event);
+
        perf_output_put(&handle, task_event->event_id);
 
        perf_event__output_id_sample(event, &handle, &sample);
@@ -5373,7 +5380,7 @@ static void perf_event_task(struct task_struct *task,
                        /* .ppid */
                        /* .tid  */
                        /* .ptid */
-                       .time = perf_clock(),
+                       /* .time */
                },
        };
 
@@ -5749,7 +5756,7 @@ static void perf_log_throttle(struct perf_event *event, int enable)
                        .misc = 0,
                        .size = sizeof(throttle_event),
                },
-               .time           = perf_clock(),
+               .time           = perf_event_clock(event),
                .id             = primary_event_id(event),
                .stream_id      = event->id,
        };
@@ -6293,6 +6300,8 @@ static int perf_swevent_init(struct perf_event *event)
 static struct pmu perf_swevent = {
        .task_ctx_nr    = perf_sw_context,
 
+       .capabilities   = PERF_PMU_CAP_NO_NMI,
+
        .event_init     = perf_swevent_init,
        .add            = perf_swevent_add,
        .del            = perf_swevent_del,
@@ -6636,6 +6645,8 @@ static int cpu_clock_event_init(struct perf_event *event)
 static struct pmu perf_cpu_clock = {
        .task_ctx_nr    = perf_sw_context,
 
+       .capabilities   = PERF_PMU_CAP_NO_NMI,
+
        .event_init     = cpu_clock_event_init,
        .add            = cpu_clock_event_add,
        .del            = cpu_clock_event_del,
@@ -6715,6 +6726,8 @@ static int task_clock_event_init(struct perf_event *event)
 static struct pmu perf_task_clock = {
        .task_ctx_nr    = perf_sw_context,
 
+       .capabilities   = PERF_PMU_CAP_NO_NMI,
+
        .event_init     = task_clock_event_init,
        .add            = task_clock_event_add,
        .del            = task_clock_event_del,
@@ -7200,6 +7213,10 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
                event->hw.target = task;
        }
 
+       event->clock = &local_clock;
+       if (parent_event)
+               event->clock = parent_event->clock;
+
        if (!overflow_handler && parent_event) {
                overflow_handler = parent_event->overflow_handler;
                context = parent_event->overflow_handler_context;
@@ -7422,6 +7439,12 @@ perf_event_set_output(struct perf_event *event, struct perf_event *output_event)
        if (output_event->cpu == -1 && output_event->ctx != event->ctx)
                goto out;
 
+       /*
+        * Mixing clocks in the same buffer is trouble you don't need.
+        */
+       if (output_event->clock != event->clock)
+               goto out;
+
 set:
        mutex_lock(&event->mmap_mutex);
        /* Can't redirect output if we've got an active mmap() */
@@ -7454,6 +7477,43 @@ static void mutex_lock_double(struct mutex *a, struct mutex *b)
        mutex_lock_nested(b, SINGLE_DEPTH_NESTING);
 }
 
+static int perf_event_set_clock(struct perf_event *event, clockid_t clk_id)
+{
+       bool nmi_safe = false;
+
+       switch (clk_id) {
+       case CLOCK_MONOTONIC:
+               event->clock = &ktime_get_mono_fast_ns;
+               nmi_safe = true;
+               break;
+
+       case CLOCK_MONOTONIC_RAW:
+               event->clock = &ktime_get_raw_fast_ns;
+               nmi_safe = true;
+               break;
+
+       case CLOCK_REALTIME:
+               event->clock = &ktime_get_real_ns;
+               break;
+
+       case CLOCK_BOOTTIME:
+               event->clock = &ktime_get_boot_ns;
+               break;
+
+       case CLOCK_TAI:
+               event->clock = &ktime_get_tai_ns;
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       if (!nmi_safe && !(event->pmu->capabilities & PERF_PMU_CAP_NO_NMI))
+               return -EINVAL;
+
+       return 0;
+}
+
 /**
  * sys_perf_event_open - open a performance event, associate it to a task/cpu
  *
@@ -7569,6 +7629,12 @@ SYSCALL_DEFINE5(perf_event_open,
         */
        pmu = event->pmu;
 
+       if (attr.use_clockid) {
+               err = perf_event_set_clock(event, attr.clockid);
+               if (err)
+                       goto err_alloc;
+       }
+
        if (group_leader &&
            (is_software_event(event) != is_software_event(group_leader))) {
                if (is_software_event(event)) {
@@ -7618,6 +7684,11 @@ SYSCALL_DEFINE5(perf_event_open,
                 */
                if (group_leader->group_leader != group_leader)
                        goto err_context;
+
+               /* All events in a group should have the same clock */
+               if (group_leader->clock != event->clock)
+                       goto err_context;
+
                /*
                 * Do not allow to attach to a group in a different
                 * task or CPU context: