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From 16104411cc5a7b20f310e3ecede85343ee6ce6b9 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Wed, 11 Feb 2015 17:28:14 -0600
Subject: [PATCH 116/124] smpboot: reuse timer calibration
NO point recalibrating for known-constant tsc... saves 200ms+ of boot time.
Author: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
---
arch/x86/kernel/tsc.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 46b2f41f8b05..88553c1f21f1 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1384,6 +1384,9 @@ unsigned long calibrate_delay_is_known(void)
if (!tsc_disabled && !cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC))
return 0;
+ if (cpu != 0)
+ return cpu_data(0).loops_per_jiffy;
+
if (!mask)
return 0;
--
2.11.1
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