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 f14cfd9d1f94c1a634833da25e86eea9cb43b864..c2241e04ea5f23f184fe559830531e64990cacd6 100644 (file)
--- 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 947554ddabb6c7779f9e9adedfc07d7891dba283..d3bebaaad842da20ce9165083825b482333ad088 100644 (file)
--- 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;
 }