[PATCH] i386 tsc: remove xtime_lock'ing around cpufreq notifier

From: Daniel Walker
Date: Wed Apr 11 2007 - 12:38:29 EST


The locking of the xtime_lock around the cpu notifier is unessesary now. At one
time the tsc was used after a frequency change for timekeeping, but the re-write
of timekeeping no longer uses the TSC unless the frequency is constant.

The variables that are changed in this section of code had also once been used
for timekeeping, but not any longer ..

Signed-Off-By: Daniel Walker <dwalker@xxxxxxxxxx>

---
arch/i386/kernel/tsc.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

Index: linux-2.6.20/arch/i386/kernel/tsc.c
===================================================================
--- linux-2.6.20.orig/arch/i386/kernel/tsc.c
+++ linux-2.6.20/arch/i386/kernel/tsc.c
@@ -200,13 +200,10 @@ time_cpufreq_notifier(struct notifier_bl
{
struct cpufreq_freqs *freq = data;

- if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
- write_seqlock_irq(&xtime_lock);
-
if (!ref_freq) {
if (!freq->old){
ref_freq = freq->new;
- goto end;
+ return 0;
}
ref_freq = freq->old;
loops_per_jiffy_ref = cpu_data[freq->cpu].loops_per_jiffy;
@@ -237,9 +234,6 @@ time_cpufreq_notifier(struct notifier_bl
}
}
}
-end:
- if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
- write_sequnlock_irq(&xtime_lock);

return 0;
}
--

--
-
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