Fix an issue with th_task_state_memo_stack and proxy/helper tasks
When proxy or helper tasks were used in inactive parallel regions, no
memo of the th_task_state was stored in the stack, so th_task_state
became invalid. This change inserts an item in the memo stack to track
these th_task_states.
Patch by Alex Duran.
Differential Revision: https://reviews.llvm.org/D145736
GitOrigin-RevId: 41f148e61d0b5a13f2406c4acf6e36ab24172a9d
diff --git a/runtime/src/kmp_tasking.cpp b/runtime/src/kmp_tasking.cpp
index e8c565c..71922ed 100644
--- a/runtime/src/kmp_tasking.cpp
+++ b/runtime/src/kmp_tasking.cpp
@@ -3934,6 +3934,44 @@
}
}
+void __kmp_shift_task_state_stack(kmp_info_t *this_thr, kmp_uint8 value) {
+ // Shift values from th_task_state_top+1 to task_state_stack_sz
+ if (this_thr->th.th_task_state_top + 1 >=
+ this_thr->th.th_task_state_stack_sz) { // increase size
+ kmp_uint32 new_size = 2 * this_thr->th.th_task_state_stack_sz;
+ kmp_uint8 *old_stack, *new_stack;
+ kmp_uint32 i;
+ new_stack = (kmp_uint8 *)__kmp_allocate(new_size);
+ for (i = 0; i <= this_thr->th.th_task_state_top; ++i) {
+ new_stack[i] = this_thr->th.th_task_state_memo_stack[i];
+ }
+ // If we need to reallocate do the shift at the same time.
+ for (; i < this_thr->th.th_task_state_stack_sz; ++i) {
+ new_stack[i + 1] = this_thr->th.th_task_state_memo_stack[i];
+ }
+ for (i = this_thr->th.th_task_state_stack_sz; i < new_size;
+ ++i) { // zero-init rest of stack
+ new_stack[i] = 0;
+ }
+ old_stack = this_thr->th.th_task_state_memo_stack;
+ this_thr->th.th_task_state_memo_stack = new_stack;
+ this_thr->th.th_task_state_stack_sz = new_size;
+ __kmp_free(old_stack);
+ } else {
+ kmp_uint8 *end;
+ kmp_uint32 i;
+
+ end = &this_thr->th
+ .th_task_state_memo_stack[this_thr->th.th_task_state_stack_sz];
+
+ for (i = this_thr->th.th_task_state_stack_sz - 1;
+ i > this_thr->th.th_task_state_top; i--, end--)
+ end[0] = end[-1];
+ }
+ this_thr->th.th_task_state_memo_stack[this_thr->th.th_task_state_top + 1] =
+ value;
+}
+
// __kmp_task_team_setup: Create a task_team for the current team, but use
// an already created, unused one if it already exists.
void __kmp_task_team_setup(kmp_info_t *this_thr, kmp_team_t *team, int always) {
@@ -3953,6 +3991,14 @@
team->t.t_task_team[this_thr->th.th_task_state], team->t.t_id,
this_thr->th.th_task_state));
}
+ if (this_thr->th.th_task_state == 1 && always && team->t.t_nproc == 1) {
+ // fix task state stack to adjust for proxy and helper tasks
+ KA_TRACE(20, ("__kmp_task_team_setup: Primary T#%d needs to shift stack"
+ " for team %d at parity=%d\n",
+ __kmp_gtid_from_thread(this_thr), team->t.t_id,
+ this_thr->th.th_task_state));
+ __kmp_shift_task_state_stack(this_thr, this_thr->th.th_task_state);
+ }
// After threads exit the release, they will call sync, and then point to this
// other task_team; make sure it is allocated and properly initialized. As
