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[ITTNOTIFY] Correct barrier imbalance time in case of tasks

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ittnotify fix for barrier imbalance time in case tasks exist. In the current
implementation, task execution time is included into aggregated time on a
barrier. This fix calculates task execution time and corrects the arrive time
by subtracting the task execution time.

Since __kmp_invoke_task() can not only be called on a barrier, the field
th.th_bar_arrive_time is used to check if the function was called at the
barrier (th.th_bar_arrive_time != 0). So for this check, th_bar_arrive_time
is set to zero right after the value is used on the barrier.

Differential Revision: http://reviews.llvm.org/D19030


git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@266332 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jonathan Peyton
2016-04-14 16:06:49 +00:00
parent be019e9440
commit 3fb06fd2fe
2 changed files with 23 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
runtime/src/kmp_barrier.cpp
+6
View File
@@ -1198,8 +1198,11 @@ __kmp_barrier(enum barrier_type bt, int gtid, int is_split, size_t reduce_size,
if( __itt_metadata_add_ptr ) {
// Initialize with master's wait time
kmp_uint64 delta = cur_time - this_thr->th.th_bar_arrive_time;
// Set arrive time to zero to be able to check it in __kmp_invoke_task(); the same is done inside the loop below
this_thr->th.th_bar_arrive_time = 0;
for (i=1; i<nproc; ++i) {
delta += ( cur_time - other_threads[i]->th.th_bar_arrive_time );
other_threads[i]->th.th_bar_arrive_time = 0;
}
__kmp_itt_metadata_imbalance(gtid, this_thr->th.th_frame_time, cur_time, delta, (kmp_uint64)( reduce != NULL));
}
@@ -1489,8 +1492,11 @@ __kmp_join_barrier(int gtid)
if( __itt_metadata_add_ptr ) {
// Initialize with master's wait time
kmp_uint64 delta = cur_time - this_thr->th.th_bar_arrive_time;
// Set arrive time to zero to be able to check it in __kmp_invoke_task(); the same is done inside the loop below
this_thr->th.th_bar_arrive_time = 0;
for (i=1; i<nproc; ++i) {
delta += ( cur_time - other_threads[i]->th.th_bar_arrive_time );
other_threads[i]->th.th_bar_arrive_time = 0;
}
__kmp_itt_metadata_imbalance(gtid, this_thr->th.th_frame_time, cur_time, delta, 0);
}
runtime/src/kmp_tasking.c
+17
View File
@@ -1103,6 +1103,7 @@ static void
__kmp_invoke_task( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t * current_task )
{
kmp_taskdata_t * taskdata = KMP_TASK_TO_TASKDATA(task);
kmp_uint64 cur_time;
#if OMP_40_ENABLED
int discard = 0 /* false */;
#endif
@@ -1126,6 +1127,13 @@ __kmp_invoke_task( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t * current_ta
}
#endif
#if USE_ITT_BUILD && USE_ITT_NOTIFY
if(__kmp_forkjoin_frames_mode == 3) {
// Get the current time stamp to measure task execution time to correct barrier imbalance time
cur_time = __itt_get_timestamp();
}
#endif
#if OMP_41_ENABLED
// Proxy tasks are not handled by the runtime
if ( taskdata->td_flags.proxy != TASK_PROXY )
@@ -1219,6 +1227,15 @@ __kmp_invoke_task( kmp_int32 gtid, kmp_task_t *task, kmp_taskdata_t * current_ta
#endif
__kmp_task_finish( gtid, task, current_task );
#if USE_ITT_BUILD && USE_ITT_NOTIFY
// Barrier imbalance - correct arrive time after the task finished
if(__kmp_forkjoin_frames_mode == 3) {
kmp_info_t *this_thr = __kmp_threads [ gtid ];
if(this_thr->th.th_bar_arrive_time) {
this_thr->th.th_bar_arrive_time += (__itt_get_timestamp() - cur_time);
}
}
#endif
KA_TRACE(30, ("__kmp_invoke_task(exit): T#%d completed task %p, resuming task %p\n",
gtid, taskdata, current_task) );
return;