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[CPUFREQ] Remove preempt_disable from powernow-k8

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Via reading the code, my understanding is that powernow-k8 uses
preempt_disable to ensure that driver->target doesn't migrate across cpus
whilst it's accessing per processor registers, however set_cpus_allowed
will provide this for us.  Additionally, remove schedule() calls from
set_cpus_allowed as set_cpus_allowed ensures that you're executing on the
target processor on return.

Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Dave Jones 2005-09-23 11:10:42 -07:00
parent df8b59be09
commit b9111b7b7f
1 changed files with 2 additions and 14 deletions
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16
arch/i386/kernel/cpu/cpufreq/powernow-k8.c
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@ -453,7 +453,6 @@ static int check_supported_cpu(unsigned int cpu)
oldmask = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(cpu));
schedule();
if (smp_processor_id() != cpu) {
printk(KERN_ERR "limiting to cpu %u failed\n", cpu);
@ -488,9 +487,7 @@ static int check_supported_cpu(unsigned int cpu)
out:
set_cpus_allowed(current, oldmask);
schedule();
return rc;
}
static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst, u8 maxvid)
@ -904,7 +901,6 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
/* only run on specific CPU from here on */
oldmask = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));
schedule();
if (smp_processor_id() != pol->cpu) {
printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
@ -959,8 +955,6 @@ static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsi
err_out:
set_cpus_allowed(current, oldmask);
schedule();
return ret;
}
@ -1017,7 +1011,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
/* only run on specific CPU from here on */
oldmask = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(pol->cpu));
schedule();
if (smp_processor_id() != pol->cpu) {
printk(KERN_ERR "limiting to cpu %u failed\n", pol->cpu);
@ -1036,7 +1029,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
/* run on any CPU again */
set_cpus_allowed(current, oldmask);
schedule();
pol->governor = CPUFREQ_DEFAULT_GOVERNOR;
pol->cpus = cpu_core_map[pol->cpu];
@ -1071,7 +1063,6 @@ static int __init powernowk8_cpu_init(struct cpufreq_policy *pol)
err_out:
set_cpus_allowed(current, oldmask);
schedule();
powernow_k8_cpu_exit_acpi(data);
kfree(data);
@ -1107,17 +1098,14 @@ static unsigned int powernowk8_get (unsigned int cpu)
set_cpus_allowed(current, oldmask);
return 0;
}
preempt_disable();
if (query_current_values_with_pending_wait(data))
goto out;
khz = find_khz_freq_from_fid(data->currfid);
out:
preempt_enable_no_resched();
out:
set_cpus_allowed(current, oldmask);
return khz;
}