From 4c698cf891a7d946b64d95ba89d6a0d255f40712 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 2 Dec 2010 15:31:27 +0100
Subject: [PATCH] re PR libgomp/43706 (scheduling two threads on one core leads
to starvation)
PR libgomp/43706
* env.c (initialize_env): Default to spin count 300000
instead of 20000000 if neither OMP_WAIT_POLICY nor GOMP_SPINCOUNT
is specified.
From-SVN: r167371
---
libgomp/ChangeLog | 5 +++++
libgomp/env.c | 4 ++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog
index 7064d6697916..4317202b211c 100644
--- a/libgomp/ChangeLog
+++ b/libgomp/ChangeLog
@@ -1,5 +1,10 @@
2010-12-02 Jakub Jelinek <jakub@redhat.com>
+ PR libgomp/43706
+ * env.c (initialize_env): Default to spin count 300000
+ instead of 20000000 if neither OMP_WAIT_POLICY nor GOMP_SPINCOUNT
+ is specified.
+
PR libgomp/45240
* parallel.c (GOMP_parallel_end): Unlock gomp_remaining_threads_lock
at the end if sync builtins aren't supported.
diff --git a/libgomp/env.c b/libgomp/env.c
index 3eb51e8a7d6d..92fa8c374979 100644
--- a/libgomp/env.c
+++ b/libgomp/env.c
@@ -502,14 +502,14 @@ initialize_env (void)
{
/* Using a rough estimation of 100000 spins per msec,
use 5 min blocking for OMP_WAIT_POLICY=active,
- 200 msec blocking when OMP_WAIT_POLICY is not specificed
+ 3 msec blocking when OMP_WAIT_POLICY is not specificed
and 0 when OMP_WAIT_POLICY=passive.
Depending on the CPU speed, this can be e.g. 5 times longer
or 5 times shorter. */
if (wait_policy > 0)
gomp_spin_count_var = 30000000000LL;
else if (wait_policy < 0)
- gomp_spin_count_var = 20000000LL;
+ gomp_spin_count_var = 300000LL;
}
/* gomp_throttled_spin_count_var is used when there are more libgomp
managed threads than available CPUs. Use very short spinning. */
--
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