35 lines
1.1 KiB
Diff
35 lines
1.1 KiB
Diff
|
From e86a8d2060f5551bc3bbb1621cce206954340cc1 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Arjan van de Ven <arjan@linux.intel.com>
|
||
|
|
Date: Wed, 11 Feb 2015 16:19:26 -0600
|
||
|
|
Subject: [PATCH 02/22] cpuidle: skip synchronize_rcu() on single CPU systems
|
||
|
|
|
||
|
|
synchronize_rcu() is pretty expensive, and on single CPU systems we don't need
|
||
|
|
it in this specific case, so skip it.
|
||
|
|
|
||
|
|
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
|
||
|
|
Signed-off-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
|
||
|
|
---
|
||
|
|
drivers/cpuidle/cpuidle.c | 5 ++++-
|
||
|
|
1 file changed, 4 insertions(+), 1 deletion(-)
|
||
|
|
|
||
|
|
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
|
||
|
|
index c73207ab..224cefc0 100644
|
||
|
|
--- a/drivers/cpuidle/cpuidle.c
|
||
|
|
+++ b/drivers/cpuidle/cpuidle.c
|
||
|
|
@@ -307,8 +307,11 @@ void cpuidle_uninstall_idle_handler(void)
|
||
|
|
/*
|
||
|
|
* Make sure external observers (such as the scheduler)
|
||
|
|
* are done looking at pointed idle states.
|
||
|
|
+ * This is only relevant if there is more than one cpu,
|
||
|
|
+ * if there is only one CPU, that is us... and we're
|
||
|
|
+ * coherent to ourselves.
|
||
|
|
*/
|
||
|
|
- synchronize_rcu();
|
||
|
|
+
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
--
|
||
|
|
2.11.0
|
||
|
|
|