[Openmp-commits] [openmp] 838dcdb - [OpenMP] libomp: minor changes to improve library performance
via Openmp-commits
openmp-commits at lists.llvm.org
Thu Feb 11 13:43:52 PST 2021
Author: AndreyChurbanov
Date: 2021-02-12T00:43:13+03:00
New Revision: 838dcdb5fc428fd4b1830a1a23bb38c1fb1c8e5a
URL: https://github.com/llvm/llvm-project/commit/838dcdb5fc428fd4b1830a1a23bb38c1fb1c8e5a
DIFF: https://github.com/llvm/llvm-project/commit/838dcdb5fc428fd4b1830a1a23bb38c1fb1c8e5a.diff
LOG: [OpenMP] libomp: minor changes to improve library performance
Three minor changes in this patch:
- added UNLIKELY hint to few rarely executed branches;
- replaced couple of run time checks with debug assertions;
- moved check of presence of ittnotify tool from inside the function call.
Differential Revision: https://reviews.llvm.org/D95816
Added:
Modified:
openmp/runtime/src/kmp_itt.h
openmp/runtime/src/kmp_tasking.cpp
Removed:
################################################################################
diff --git a/openmp/runtime/src/kmp_itt.h b/openmp/runtime/src/kmp_itt.h
index b14a19301459..6b64cd461f3c 100644
--- a/openmp/runtime/src/kmp_itt.h
+++ b/openmp/runtime/src/kmp_itt.h
@@ -90,6 +90,16 @@ __kmp_inline void __kmp_itt_barrier_finished(int gtid, void *object);
__kmp_inline void *__kmp_itt_taskwait_object(int gtid);
__kmp_inline void __kmp_itt_taskwait_starting(int gtid, void *object);
__kmp_inline void __kmp_itt_taskwait_finished(int gtid, void *object);
+#define KMP_ITT_TASKWAIT_STARTING(obj) \
+ if (UNLIKELY(__itt_sync_create_ptr)) { \
+ obj = __kmp_itt_taskwait_object(gtid); \
+ if (obj != NULL) { \
+ __kmp_itt_taskwait_starting(gtid, obj); \
+ } \
+ }
+#define KMP_ITT_TASKWAIT_FINISHED(obj) \
+ if (UNLIKELY(obj != NULL)) \
+ __kmp_itt_taskwait_finished(gtid, obj);
// --- Task reporting ---
__kmp_inline void __kmp_itt_task_starting(void *object);
diff --git a/openmp/runtime/src/kmp_tasking.cpp b/openmp/runtime/src/kmp_tasking.cpp
index b680767d9094..876cd2505c77 100644
--- a/openmp/runtime/src/kmp_tasking.cpp
+++ b/openmp/runtime/src/kmp_tasking.cpp
@@ -620,7 +620,7 @@ static void __kmpc_omp_task_begin_if0_template(ident_t *loc_ref, kmp_int32 gtid,
"current_task=%p\n",
gtid, loc_ref, taskdata, current_task));
- if (taskdata->td_flags.tiedness == TASK_UNTIED) {
+ if (UNLIKELY(taskdata->td_flags.tiedness == TASK_UNTIED)) {
// untied task needs to increment counter so that the task structure is not
// freed prematurely
kmp_int32 counter = 1 + KMP_ATOMIC_INC(&taskdata->td_untied_count);
@@ -883,7 +883,7 @@ static void __kmp_task_finish(kmp_int32 gtid, kmp_task_t *task,
hence overlapping the destructor invocations with some other work in the
released tasks. The OpenMP spec is not specific on when the destructors
are invoked, so we should be free to choose. */
- if (taskdata->td_flags.destructors_thunk) {
+ if (UNLIKELY(taskdata->td_flags.destructors_thunk)) {
kmp_routine_entry_t destr_thunk = task->data1.destructors;
KMP_ASSERT(destr_thunk);
destr_thunk(gtid, task);
@@ -894,7 +894,7 @@ static void __kmp_task_finish(kmp_int32 gtid, kmp_task_t *task,
KMP_DEBUG_ASSERT(taskdata->td_flags.freed == 0);
bool detach = false;
- if (taskdata->td_flags.detachable == TASK_DETACHABLE) {
+ if (UNLIKELY(taskdata->td_flags.detachable == TASK_DETACHABLE)) {
if (taskdata->td_allow_completion_event.type ==
KMP_EVENT_ALLOW_COMPLETION) {
// event hasn't been fulfilled yet. Try to detach task.
@@ -987,7 +987,7 @@ static void __kmpc_omp_task_complete_if0_template(ident_t *loc_ref,
kmp_task_t *task) {
KA_TRACE(10, ("__kmpc_omp_task_complete_if0(enter): T#%d loc=%p task=%p\n",
gtid, loc_ref, KMP_TASK_TO_TASKDATA(task)));
- __kmp_assert_valid_gtid(gtid);
+ KMP_DEBUG_ASSERT(gtid >= 0);
// this routine will provide task to resume
__kmp_task_finish<ompt>(gtid, task, NULL);
@@ -1234,8 +1234,8 @@ kmp_task_t *__kmp_task_alloc(ident_t *loc_ref, kmp_int32 gtid,
// Detachable tasks are not proxy tasks yet but could be in the future. Doing
// the tasking setup
// when that happens is too late.
- if (flags->proxy == TASK_PROXY || flags->detachable == TASK_DETACHABLE ||
- flags->hidden_helper) {
+ if (UNLIKELY(flags->proxy == TASK_PROXY ||
+ flags->detachable == TASK_DETACHABLE || flags->hidden_helper)) {
if (flags->proxy == TASK_PROXY) {
flags->tiedness = TASK_UNTIED;
flags->merged_if0 = 1;
@@ -1875,7 +1875,7 @@ static kmp_int32 __kmpc_omp_taskwait_template(ident_t *loc_ref, kmp_int32 gtid,
KMP_SET_THREAD_STATE_BLOCK(TASKWAIT);
KA_TRACE(10, ("__kmpc_omp_taskwait(enter): T#%d loc=%p\n", gtid, loc_ref));
- __kmp_assert_valid_gtid(gtid);
+ KMP_DEBUG_ASSERT(gtid >= 0);
if (__kmp_tasking_mode != tskm_immediate_exec) {
thread = __kmp_threads[gtid];
@@ -1915,9 +1915,10 @@ static kmp_int32 __kmpc_omp_taskwait_template(ident_t *loc_ref, kmp_int32 gtid,
taskdata->td_taskwait_thread = gtid + 1;
#if USE_ITT_BUILD
- void *itt_sync_obj = __kmp_itt_taskwait_object(gtid);
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_starting(gtid, itt_sync_obj);
+ void *itt_sync_obj = NULL;
+#if USE_ITT_NOTIFY
+ KMP_ITT_TASKWAIT_STARTING(itt_sync_obj);
+#endif /* USE_ITT_NOTIFY */
#endif /* USE_ITT_BUILD */
bool must_wait =
@@ -1943,8 +1944,7 @@ static kmp_int32 __kmpc_omp_taskwait_template(ident_t *loc_ref, kmp_int32 gtid,
}
}
#if USE_ITT_BUILD
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_finished(gtid, itt_sync_obj);
+ KMP_ITT_TASKWAIT_FINISHED(itt_sync_obj);
KMP_FSYNC_ACQUIRED(taskdata); // acquire self - sync with children
#endif /* USE_ITT_BUILD */
@@ -2028,9 +2028,10 @@ kmp_int32 __kmpc_omp_taskyield(ident_t *loc_ref, kmp_int32 gtid, int end_part) {
taskdata->td_taskwait_thread = gtid + 1;
#if USE_ITT_BUILD
- void *itt_sync_obj = __kmp_itt_taskwait_object(gtid);
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_starting(gtid, itt_sync_obj);
+ void *itt_sync_obj = NULL;
+#if USE_ITT_NOTIFY
+ KMP_ITT_TASKWAIT_STARTING(itt_sync_obj);
+#endif /* USE_ITT_NOTIFY */
#endif /* USE_ITT_BUILD */
if (!taskdata->td_flags.team_serial) {
kmp_task_team_t *task_team = thread->th.th_task_team;
@@ -2052,8 +2053,7 @@ kmp_int32 __kmpc_omp_taskyield(ident_t *loc_ref, kmp_int32 gtid, int end_part) {
}
}
#if USE_ITT_BUILD
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_finished(gtid, itt_sync_obj);
+ KMP_ITT_TASKWAIT_FINISHED(itt_sync_obj);
#endif /* USE_ITT_BUILD */
// Debugger: The taskwait is completed. Location remains, but thread is
@@ -2553,9 +2553,10 @@ void __kmpc_end_taskgroup(ident_t *loc, int gtid) {
#if USE_ITT_BUILD
// For ITT the taskgroup wait is similar to taskwait until we need to
// distinguish them
- void *itt_sync_obj = __kmp_itt_taskwait_object(gtid);
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_starting(gtid, itt_sync_obj);
+ void *itt_sync_obj = NULL;
+#if USE_ITT_NOTIFY
+ KMP_ITT_TASKWAIT_STARTING(itt_sync_obj);
+#endif /* USE_ITT_NOTIFY */
#endif /* USE_ITT_BUILD */
#if OMPT_SUPPORT && OMPT_OPTIONAL
@@ -2588,8 +2589,7 @@ void __kmpc_end_taskgroup(ident_t *loc, int gtid) {
#endif
#if USE_ITT_BUILD
- if (UNLIKELY(itt_sync_obj != NULL))
- __kmp_itt_taskwait_finished(gtid, itt_sync_obj);
+ KMP_ITT_TASKWAIT_FINISHED(itt_sync_obj);
KMP_FSYNC_ACQUIRED(taskdata); // acquire self - sync with descendants
#endif /* USE_ITT_BUILD */
}
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