From 16e2011be67b8625c1c600f9742c2279be3c0c68 Mon Sep 17 00:00:00 2001
From: Glauber de Oliveira Costa <gcosta@redhat.com>
Date: Wed, 30 Jan 2008 13:31:03 +0100
Subject: [PATCH] x86: allow sched clock to be overridden by paravirt
This patch turns the sched_clock into native_sched_clock.
sched clock becomes a weak symbol, which can then give its
place to a paravirt definition.
Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/tsc_64.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 32edd2c50e9..204a9080af0 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -63,7 +63,7 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
local_irq_restore(flags);
}
-unsigned long long sched_clock(void)
+unsigned long long native_sched_clock(void)
{
unsigned long a = 0;
@@ -77,6 +77,19 @@ unsigned long long sched_clock(void)
return cycles_2_ns(a);
}
+/* We need to define a real function for sched_clock, to override the
+ weak default version */
+#ifdef CONFIG_PARAVIRT
+unsigned long long sched_clock(void)
+{
+ return paravirt_sched_clock();
+}
+#else
+unsigned long long
+sched_clock(void) __attribute__((alias("native_sched_clock")));
+#endif
+
+
static int tsc_unstable;
inline int check_tsc_unstable(void)
--
2.20.1