1 #include <unistd.h> 2 #include <math.h> 3 #include <sys/time.h> 4 #include <time.h> 5 6 #include "fio.h" 7 #include "smalloc.h" 8 9 struct timeval *fio_tv = NULL; 10 int fio_gtod_offload = 0; 11 int fio_gtod_cpu = -1; 12 static pthread_t gtod_thread; 13 14 void fio_gtod_init(void) 15 { 16 fio_tv = smalloc(sizeof(struct timeval)); 17 if (!fio_tv) 18 log_err("fio: smalloc pool exhausted\n"); 19 } 20 21 static void fio_gtod_update(void) 22 { 23 if (fio_tv) 24 gettimeofday(fio_tv, NULL); 25 } 26 27 static void *gtod_thread_main(void *data) 28 { 29 struct fio_mutex *mutex = data; 30 31 fio_mutex_up(mutex); 32 33 /* 34 * As long as we have jobs around, update the clock. It would be nice 35 * to have some way of NOT hammering that CPU with gettimeofday(), 36 * but I'm not sure what to use outside of a simple CPU nop to relax 37 * it - we don't want to lose precision. 38 */ 39 while (threads) { 40 fio_gtod_update(); 41 nop; 42 } 43 44 return NULL; 45 } 46 47 int fio_start_gtod_thread(void) 48 { 49 struct fio_mutex *mutex; 50 pthread_attr_t attr; 51 int ret; 52 53 mutex = fio_mutex_init(FIO_MUTEX_LOCKED); 54 if (!mutex) 55 return 1; 56 57 pthread_attr_init(&attr); 58 pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN); 59 ret = pthread_create(>od_thread, &attr, gtod_thread_main, NULL); 60 pthread_attr_destroy(&attr); 61 if (ret) { 62 log_err("Can't create gtod thread: %s\n", strerror(ret)); 63 goto err; 64 } 65 66 ret = pthread_detach(gtod_thread); 67 if (ret) { 68 log_err("Can't detatch gtod thread: %s\n", strerror(ret)); 69 goto err; 70 } 71 72 dprint(FD_MUTEX, "wait on startup_mutex\n"); 73 fio_mutex_down(mutex); 74 dprint(FD_MUTEX, "done waiting on startup_mutex\n"); 75 err: 76 fio_mutex_remove(mutex); 77 return ret; 78 } 79 80 81
