diff options
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 14 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/perf_event.h | 6 | ||||
| -rw-r--r-- | kernel/events/core.c | 77 |
4 files changed, 91 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index ac41b3ad1fc9..0420ebcac116 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1978,13 +1978,23 @@ void arch_perf_update_userpage(struct perf_event *event, data = cyc2ns_read_begin(); + /* + * Internal timekeeping for enabled/running/stopped times + * is always in the local_clock domain. + */ userpg->cap_user_time = 1; userpg->time_mult = data->cyc2ns_mul; userpg->time_shift = data->cyc2ns_shift; userpg->time_offset = data->cyc2ns_offset - now; - userpg->cap_user_time_zero = 1; - userpg->time_zero = data->cyc2ns_offset; + /* + * cap_user_time_zero doesn't make sense when we're using a different + * time base for the records. + */ + if (event->clock == &local_clock) { + userpg->cap_user_time_zero = 1; + userpg->time_zero = data->cyc2ns_offset; + } cyc2ns_read_end(data); } diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b16eac5f54ce..401554074de9 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -173,6 +173,7 @@ struct perf_event; * pmu::capabilities flags */ #define PERF_PMU_CAP_NO_INTERRUPT 0x01 +#define PERF_PMU_CAP_NO_NMI 0x02 /** * struct pmu - generic performance monitoring unit @@ -457,6 +458,7 @@ struct perf_event { struct pid_namespace *ns; u64 id; + u64 (*clock)(void); perf_overflow_handler_t overflow_handler; void *overflow_handler_context; diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 1e3cd07cf76e..3bb40ddadbe5 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -326,7 +326,8 @@ struct perf_event_attr { exclude_callchain_user : 1, /* exclude user callchains */ mmap2 : 1, /* include mmap with inode data */ comm_exec : 1, /* flag comm events that are due to an exec */ - __reserved_1 : 39; + use_clockid : 1, /* use @clockid for time fields */ + __reserved_1 : 38; union { __u32 wakeup_events; /* wakeup every n events */ @@ -355,8 +356,7 @@ struct perf_event_attr { */ __u32 sample_stack_user; - /* Align to u64. */ - __u32 __reserved_2; + __s32 clockid; /* * Defines set of regs to dump for each sample * state captured on: diff --git a/kernel/events/core.c b/kernel/events/core.c index bb1a7c36e794..c40c2cac2d8e 100644 --- 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: |