From: Karsten Wiese <fzu@wemgehoertderstaat.de>
Date: Mon, 7 Apr 2008 10:14:45 +0000 (+0200)
Subject: x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4f41c94d5c24e3b3453e9df03c0a80ca1acf00d2;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier()

In time_cpufreq_notifier() the cpu id to act upon is held in freq->cpu. Use it
instead of smp_processor_id() in the call to set_cyc2ns_scale().
This makes the preempt_*able() unnecessary and lets set_cyc2ns_scale() update
the intended cpu's cyc2ns.

Related mail/thread: http://lkml.org/lkml/2007/12/7/130

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index f14cfd9d1f94..c2241e04ea5f 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -256,9 +256,7 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
 						ref_freq, freq->new);
 			if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
 				tsc_khz = cpu_khz;
-				preempt_disable();
-				set_cyc2ns_scale(cpu_khz, smp_processor_id());
-				preempt_enable();
+				set_cyc2ns_scale(cpu_khz, freq->cpu);
 				/*
 				 * TSC based sched_clock turns
 				 * to junk w/ cpufreq
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 947554ddabb6..d3bebaaad842 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -148,9 +148,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
 			mark_tsc_unstable("cpufreq changes");
 	}
 
-	preempt_disable();
-	set_cyc2ns_scale(tsc_khz_ref, smp_processor_id());
-	preempt_enable();
+	set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
 
 	return 0;
 }