Commit df3624aa authored May 02, 2007 by Daniel Walker Committed by Andi Kleen May 02, 2007

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



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>

parent 62918a03

arch/i386/kernel/tsc.c

+1 −7

Original line number	Diff line number	Diff line
		@@ -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;
		}

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