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