[OpenMP] Clean up load balancing dynamic mode
This patch cleans up the bookkeeping code for the load balancing dynamic mode.
When a thread is moved to or from the thread pool, the th_active_in_pool flag
and the __kmp_thread_pool_active_nth global counter are both updated. This
removes the need for the corrective code in the main wait loop. Another global
counter, __kmp_thread_pool_nth, was removed completely, as it was only used for
debugging, but was not under KMP_DEBUG.
Patch by Terry Wilmarth
Differential Revision: https://reviews.llvm.org/D59508
llvm-svn: 357927
diff --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
index 6b6ebee..6672631 100644
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -4264,15 +4264,24 @@
__kmp_thread_pool_insert_pt = NULL;
}
TCW_4(new_thr->th.th_in_pool, FALSE);
- // Don't touch th_active_in_pool or th_active.
- // The worker thread adjusts those flags as it sleeps/awakens.
- __kmp_thread_pool_nth--;
+ __kmp_suspend_initialize_thread(new_thr);
+ __kmp_lock_suspend_mx(new_thr);
+ if (new_thr->th.th_active_in_pool == TRUE) {
+ KMP_DEBUG_ASSERT(new_thr->th.th_active == TRUE);
+ KMP_ATOMIC_DEC(&__kmp_thread_pool_active_nth);
+ new_thr->th.th_active_in_pool = FALSE;
+ }
+#if KMP_DEBUG
+ else {
+ KMP_DEBUG_ASSERT(new_thr->th.th_active == FALSE);
+ }
+#endif
+ __kmp_unlock_suspend_mx(new_thr);
KA_TRACE(20, ("__kmp_allocate_thread: T#%d using thread T#%d\n",
__kmp_get_gtid(), new_thr->th.th_info.ds.ds_gtid));
KMP_ASSERT(!new_thr->th.th_team);
KMP_DEBUG_ASSERT(__kmp_nth < __kmp_threads_capacity);
- KMP_DEBUG_ASSERT(__kmp_thread_pool_nth >= 0);
/* setup the thread structure */
__kmp_initialize_info(new_thr, team, new_tid,
@@ -5705,7 +5714,18 @@
(this_th->th.th_info.ds.ds_gtid <
this_th->th.th_next_pool->th.th_info.ds.ds_gtid));
TCW_4(this_th->th.th_in_pool, TRUE);
- __kmp_thread_pool_nth++;
+ __kmp_suspend_initialize_thread(this_th);
+ __kmp_lock_suspend_mx(this_th);
+ if (this_th->th.th_active == TRUE) {
+ KMP_ATOMIC_INC(&__kmp_thread_pool_active_nth);
+ this_th->th.th_active_in_pool = TRUE;
+ }
+#if KMP_DEBUG
+ else {
+ KMP_DEBUG_ASSERT(this_th->th.th_active_in_pool == FALSE);
+ }
+#endif
+ __kmp_unlock_suspend_mx(this_th);
TCW_4(__kmp_nth, __kmp_nth - 1);
@@ -5954,10 +5974,6 @@
KMP_ATOMIC_DEC(&__kmp_thread_pool_active_nth);
KMP_DEBUG_ASSERT(__kmp_thread_pool_active_nth >= 0);
}
-
- // Decrement # of [worker] threads in the pool.
- KMP_DEBUG_ASSERT(__kmp_thread_pool_nth > 0);
- --__kmp_thread_pool_nth;
}
__kmp_free_implicit_task(thread);
@@ -6099,6 +6115,8 @@
KMP_DEBUG_ASSERT(thread->th.th_reap_state == KMP_SAFE_TO_REAP);
thread->th.th_next_pool = NULL;
thread->th.th_in_pool = FALSE;
+ thread->th.th_active_in_pool = FALSE;
+ KMP_ATOMIC_DEC(&__kmp_thread_pool_active_nth);
__kmp_reap_thread(thread, 0);
}
__kmp_thread_pool_insert_pt = NULL;