From 581fdbaad4e0becaf738ca34d9bf907e86248408 Mon Sep 17 00:00:00 2001
From: Jonathan Peyton <jonathan.l.peyton@intel.com>
Date: Wed, 15 Feb 2017 17:19:21 +0000
Subject: Enable yield cycle on Linux

This change allows the runtime to turn __kmp_yield() on/off repeatedly on Linux.
This feature was removed when disabling monitor thread, but there are
applications that perform better with this feature on.

Patch by Hansang Bae

Differential Revision: https://reviews.llvm.org/D29227

llvm-svn: 295203
---
 openmp/runtime/src/z_Linux_util.cpp | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

(limited to 'openmp/runtime/src/z_Linux_util.cpp')

diff --git a/openmp/runtime/src/z_Linux_util.cpp b/openmp/runtime/src/z_Linux_util.cpp
index b9490ea65d3..8cba1ff5607 100644
--- a/openmp/runtime/src/z_Linux_util.cpp
+++ b/openmp/runtime/src/z_Linux_util.cpp
@@ -1812,13 +1812,16 @@ __kmp_resume_monitor()
 void
 __kmp_yield( int cond )
 {
-    if (cond
+    if (!cond)
+        return;
 #if KMP_USE_MONITOR
-        && __kmp_yielding_on
+    if (!__kmp_yielding_on)
+        return;
+#else
+    if (__kmp_yield_cycle && !KMP_YIELD_NOW())
+        return;
 #endif
-    ) {
-        sched_yield();
-    }
+    sched_yield();
 }
 
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