[CPUFREQ] Remove preempt_disable from powernow-k8

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>

diff --git a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
index ab6e0611303d4f8b86f694b6c8aaab9e04b2cae3..e2e03eebedf6ba1254c325b5bcbd7de8c2c19018 100644 (file)
--- a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c
@@ -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;
 }