[PATCH] i386: remove xtime_lock'ing around cpufreq notifier
authorDaniel Walker <dwalker@mvista.com>
Wed, 2 May 2007 17:27:18 +0000 (19:27 +0200)
committerAndi Kleen <andi@basil.nowhere.org>
Wed, 2 May 2007 17:27:18 +0000 (19:27 +0200)
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@mvista.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
arch/i386/kernel/tsc.c

index 755209d..f64b81f 100644 (file)
@@ -200,13 +200,10 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
 {
        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_block *nb, unsigned long val, void *data)
                        }
                }
        }
-end:
-       if (val != CPUFREQ_RESUMECHANGE && val != CPUFREQ_SUSPENDCHANGE)
-               write_sequnlock_irq(&xtime_lock);
 
        return 0;
 }