diff options
| -rw-r--r-- | tools/perf/builtin-sched.c | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 19f43faa9f81..b12b23ac06f3 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -13,7 +13,6 @@ #include "util/debug.h" #include "util/data_map.h" -#include <sys/types.h> #include <sys/prctl.h> #include <semaphore.h> @@ -414,34 +413,33 @@ static u64 get_cpu_usage_nsec_parent(void) return sum; } -static u64 get_cpu_usage_nsec_self(void) +static int self_open_counters(void) { - char filename [] = "/proc/1234567890/sched"; - unsigned long msecs, nsecs; - char *line = NULL; - u64 total = 0; - size_t len = 0; - ssize_t chars; - FILE *file; - int ret; + struct perf_event_attr attr; + int fd; - sprintf(filename, "/proc/%d/sched", getpid()); - file = fopen(filename, "r"); - BUG_ON(!file); + memset(&attr, 0, sizeof(attr)); - while ((chars = getline(&line, &len, file)) != -1) { - ret = sscanf(line, "se.sum_exec_runtime : %ld.%06ld\n", - &msecs, &nsecs); - if (ret == 2) { - total = msecs*1e6 + nsecs; - break; - } - } - if (line) - free(line); - fclose(file); + attr.type = PERF_TYPE_SOFTWARE; + attr.config = PERF_COUNT_SW_TASK_CLOCK; - return total; + fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + + if (fd < 0) + die("Error: sys_perf_event_open() syscall returned" + "with %d (%s)\n", fd, strerror(errno)); + return fd; +} + +static u64 get_cpu_usage_nsec_self(int fd) +{ + u64 runtime; + int ret; + + ret = read(fd, &runtime, sizeof(runtime)); + BUG_ON(ret != sizeof(runtime)); + + return runtime; } static void *thread_func(void *ctx) @@ -450,9 +448,11 @@ static void *thread_func(void *ctx) u64 cpu_usage_0, cpu_usage_1; unsigned long i, ret; char comm2[22]; + int fd; sprintf(comm2, ":%s", this_task->comm); prctl(PR_SET_NAME, comm2); + fd = self_open_counters(); again: ret = sem_post(&this_task->ready_for_work); @@ -462,16 +462,15 @@ again: ret = pthread_mutex_unlock(&start_work_mutex); BUG_ON(ret); - cpu_usage_0 = get_cpu_usage_nsec_self(); + cpu_usage_0 = get_cpu_usage_nsec_self(fd); for (i = 0; i < this_task->nr_events; i++) { this_task->curr_event = i; process_sched_event(this_task, this_task->atoms[i]); } - cpu_usage_1 = get_cpu_usage_nsec_self(); + cpu_usage_1 = get_cpu_usage_nsec_self(fd); this_task->cpu_usage = cpu_usage_1 - cpu_usage_0; - ret = sem_post(&this_task->work_done_sem); BUG_ON(ret); |