diff options
Diffstat (limited to 'openmp/runtime/src/kmp_wait_release.h')
| -rw-r--r-- | openmp/runtime/src/kmp_wait_release.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/openmp/runtime/src/kmp_wait_release.h b/openmp/runtime/src/kmp_wait_release.h index c8f6b5c2be0..22ff8e84224 100644 --- a/openmp/runtime/src/kmp_wait_release.h +++ b/openmp/runtime/src/kmp_wait_release.h @@ -84,6 +84,22 @@ class kmp_flag { */ }; +#if ! KMP_USE_MONITOR +# if KMP_OS_UNIX && (KMP_ARCH_X86 || KMP_ARCH_X86_64) + // HW TSC is used to reduce overhead (clock tick instead of nanosecond). + extern double __kmp_ticks_per_nsec; +# define KMP_NOW() __kmp_hardware_timestamp() +# define KMP_BLOCKTIME_INTERVAL() (__kmp_dflt_blocktime * KMP_USEC_PER_SEC * __kmp_ticks_per_nsec) +# define KMP_BLOCKING(goal, count) ((goal) > KMP_NOW()) +# else + // System time is retrieved sporadically while blocking. + extern kmp_uint64 __kmp_now_nsec(); +# define KMP_NOW() __kmp_now_nsec() +# define KMP_BLOCKTIME_INTERVAL() (__kmp_dflt_blocktime * KMP_USEC_PER_SEC) +# define KMP_BLOCKING(goal, count) ((count) % 1000 != 0 || (goal) > KMP_NOW()) +# endif +#endif + /* Spin wait loop that first does pause, then yield, then sleep. A thread that calls __kmp_wait_* must make certain that another thread calls __kmp_release to wake it back up to prevent deadlocks! */ template <class C> @@ -98,6 +114,10 @@ __kmp_wait_template(kmp_info_t *this_thr, C *flag, int final_spin int th_gtid; int tasks_completed = FALSE; int oversubscribed; +#if ! KMP_USE_MONITOR + kmp_uint64 poll_count; + kmp_uint64 hibernate_goal; +#endif KMP_FSYNC_SPIN_INIT(spin, NULL); if (flag->done_check()) { @@ -142,6 +162,7 @@ __kmp_wait_template(kmp_info_t *this_thr, C *flag, int final_spin KMP_INIT_YIELD(spins); if (__kmp_dflt_blocktime != KMP_MAX_BLOCKTIME) { +#if KMP_USE_MONITOR // The worker threads cannot rely on the team struct existing at this point. // Use the bt values cached in the thread struct instead. #ifdef KMP_ADJUST_BLOCKTIME @@ -165,6 +186,10 @@ __kmp_wait_template(kmp_info_t *this_thr, C *flag, int final_spin KF_TRACE(20, ("__kmp_wait_sleep: T#%d now=%d, hibernate=%d, intervals=%d\n", th_gtid, __kmp_global.g.g_time.dt.t_value, hibernate, hibernate - __kmp_global.g.g_time.dt.t_value)); +#else + hibernate_goal = KMP_NOW() + KMP_BLOCKTIME_INTERVAL(); + poll_count = 0; +#endif // KMP_USE_MONITOR } oversubscribed = (TCR_4(__kmp_nth) > __kmp_avail_proc); @@ -246,9 +271,14 @@ __kmp_wait_template(kmp_info_t *this_thr, C *flag, int final_spin if ((task_team != NULL) && TCR_4(task_team->tt.tt_found_tasks)) continue; +#if KMP_USE_MONITOR // If we have waited a bit more, fall asleep if (TCR_4(__kmp_global.g.g_time.dt.t_value) < hibernate) continue; +#else + if (KMP_BLOCKING(hibernate_goal, poll_count++)) + continue; +#endif KF_TRACE(50, ("__kmp_wait_sleep: T#%d suspend time reached\n", th_gtid)); |
