diff options
| -rw-r--r-- | include/linux/perf_event.h | 3 | ||||
| -rw-r--r-- | kernel/events/core.c | 25 |
2 files changed, 26 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 6f7459f72dfd..5c5362584aba 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -514,8 +514,11 @@ typedef void (*perf_overflow_handler_t)(struct perf_event *, * Event capabilities. For event_caps and groups caps. * * PERF_EV_CAP_SOFTWARE: Is a software event. + * PERF_EV_CAP_READ_ACTIVE_PKG: A CPU event (or cgroup event) that can be read + * from any CPU in the package where it is active. */ #define PERF_EV_CAP_SOFTWARE BIT(0) +#define PERF_EV_CAP_READ_ACTIVE_PKG BIT(1) #define SWEVENT_HLIST_BITS 8 #define SWEVENT_HLIST_SIZE (1 << SWEVENT_HLIST_BITS) diff --git a/kernel/events/core.c b/kernel/events/core.c index 8c42a5ae9030..3f07e6cfc1b6 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -3424,6 +3424,22 @@ struct perf_read_data { int ret; }; +static int find_cpu_to_read(struct perf_event *event, int local_cpu) +{ + int event_cpu = event->oncpu; + u16 local_pkg, event_pkg; + + if (event->group_caps & PERF_EV_CAP_READ_ACTIVE_PKG) { + event_pkg = topology_physical_package_id(event_cpu); + local_pkg = topology_physical_package_id(local_cpu); + + if (event_pkg == local_pkg) + return local_cpu; + } + + return event_cpu; +} + /* * Cross CPU call to read the hardware event */ @@ -3545,7 +3561,7 @@ u64 perf_event_read_local(struct perf_event *event) static int perf_event_read(struct perf_event *event, bool group) { - int ret = 0; + int ret = 0, cpu_to_read, local_cpu; /* * If event is enabled and currently active on a CPU, update the @@ -3557,7 +3573,12 @@ static int perf_event_read(struct perf_event *event, bool group) .group = group, .ret = 0, }; - ret = smp_call_function_single(event->oncpu, __perf_event_read, &data, 1); + + local_cpu = get_cpu(); + cpu_to_read = find_cpu_to_read(event, local_cpu); + put_cpu(); + + ret = smp_call_function_single(cpu_to_read, __perf_event_read, &data, 1); /* The event must have been read from an online CPU: */ WARN_ON_ONCE(ret); ret = ret ? : data.ret; |