[Openmp-commits] [PATCH] D105715: [OpenMP] Minor improvement in task allocation

[Hansang Bae via Phabricator via Openmp-commits]

hbae created this revision.
hbae added reviewers: AndreyChurbanov, tlwilmar, jlpeyton, Nawrin.
hbae added a project: OpenMP.
Herald added subscribers: jfb, guansong, yaxunl.
hbae requested review of this revision.
Herald added a reviewer: jdoerfert.
Herald added a subscriber: sstefan1.

This patch includes a few changes to improve task allocation
performance slightly. These changes are enough to restore performance
drop observed after introducing hidden helper.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D105715

Files:
  openmp/runtime/src/kmp_tasking.cpp


Index: openmp/runtime/src/kmp_tasking.cpp
===================================================================
--- openmp/runtime/src/kmp_tasking.cpp
+++ openmp/runtime/src/kmp_tasking.cpp
@@ -1184,10 +1184,10 @@
 // in task.
 // task_entry: Pointer to task code entry point generated by compiler.
 // returns: a pointer to the allocated kmp_task_t structure (task).
-kmp_task_t *__kmp_task_alloc(ident_t *loc_ref, kmp_int32 gtid,
-                             kmp_tasking_flags_t *flags,
-                             size_t sizeof_kmp_task_t, size_t sizeof_shareds,
-                             kmp_routine_entry_t task_entry) {
+static inline kmp_task_t *
+__kmp_task_alloc_impl(ident_t *loc_ref, kmp_int32 gtid,
+                      kmp_tasking_flags_t *flags, size_t sizeof_kmp_task_t,
+                      size_t sizeof_shareds, kmp_routine_entry_t task_entry) {
   kmp_task_t *task;
   kmp_taskdata_t *taskdata;
   kmp_info_t *thread = __kmp_threads[gtid];
@@ -1344,13 +1344,7 @@
   if (flags->proxy == TASK_FULL)
     copy_icvs(&taskdata->td_icvs, &taskdata->td_parent->td_icvs);
 
-  taskdata->td_flags.tiedness = flags->tiedness;
-  taskdata->td_flags.final = flags->final;
-  taskdata->td_flags.merged_if0 = flags->merged_if0;
-  taskdata->td_flags.destructors_thunk = flags->destructors_thunk;
-  taskdata->td_flags.proxy = flags->proxy;
-  taskdata->td_flags.detachable = flags->detachable;
-  taskdata->td_flags.hidden_helper = flags->hidden_helper;
+  taskdata->td_flags = *flags;
   taskdata->encountering_gtid = gtid;
   taskdata->td_task_team = thread->th.th_task_team;
   taskdata->td_size_alloc = shareds_offset + sizeof_shareds;
@@ -1375,8 +1369,6 @@
   taskdata->td_flags.complete = 0;
   taskdata->td_flags.freed = 0;
 
-  taskdata->td_flags.native = flags->native;
-
   KMP_ATOMIC_ST_RLX(&taskdata->td_incomplete_child_tasks, 0);
   // start at one because counts current task and children
   KMP_ATOMIC_ST_RLX(&taskdata->td_allocated_child_tasks, 1);
@@ -1406,12 +1398,11 @@
     if (taskdata->td_parent->td_flags.tasktype == TASK_EXPLICIT) {
       KMP_ATOMIC_INC(&taskdata->td_parent->td_allocated_child_tasks);
     }
-  }
-
-  if (flags->hidden_helper) {
-    taskdata->td_flags.task_serial = FALSE;
-    // Increment the number of hidden helper tasks to be executed
-    KMP_ATOMIC_INC(&__kmp_unexecuted_hidden_helper_tasks);
+    if (flags->hidden_helper) {
+      taskdata->td_flags.task_serial = FALSE;
+      // Increment the number of hidden helper tasks to be executed
+      KMP_ATOMIC_INC(&__kmp_unexecuted_hidden_helper_tasks);
+    }
   }
 
   KA_TRACE(20, ("__kmp_task_alloc(exit): T#%d created task %p parent=%p\n",
@@ -1421,6 +1412,14 @@
   return task;
 }
 
+kmp_task_t *__kmp_task_alloc(ident_t *loc_ref, kmp_int32 gtid,
+                             kmp_tasking_flags_t *flags,
+                             size_t sizeof_kmp_task_t, size_t sizeof_shareds,
+                             kmp_routine_entry_t task_entry) {
+  return __kmp_task_alloc_impl(loc_ref, gtid, flags, sizeof_kmp_task_t,
+                               sizeof_shareds, task_entry);
+}
+
 kmp_task_t *__kmpc_omp_task_alloc(ident_t *loc_ref, kmp_int32 gtid,
                                   kmp_int32 flags, size_t sizeof_kmp_task_t,
                                   size_t sizeof_shareds,
@@ -1437,8 +1436,8 @@
                 input_flags->detachable ? "detachable" : "", sizeof_kmp_task_t,
                 sizeof_shareds, task_entry));
 
-  retval = __kmp_task_alloc(loc_ref, gtid, input_flags, sizeof_kmp_task_t,
-                            sizeof_shareds, task_entry);
+  retval = __kmp_task_alloc_impl(loc_ref, gtid, input_flags, sizeof_kmp_task_t,
+                                 sizeof_shareds, task_entry);
 
   KA_TRACE(20, ("__kmpc_omp_task_alloc(exit): T#%d retval %p\n", gtid, retval));
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D105715.357564.patch
Type: text/x-patch
Size: 3831 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/openmp-commits/attachments/20210709/fb5cf5ac/attachment-0001.bin>