From b9111b7b7f46b0ec1ccb451d60ec439b92e4df65 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Fri, 23 Sep 2005 11:10:42 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- arch/i386/kernel/cpu/cpufreq/powernow-k8.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/arch/i386/kernel/cpu/cpufreq/powernow-k8.c b/arch/i386/kernel/cpu/cpufreq/powernow-k8.c index ab6e061130..e2e03eebed 100644 --- 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; } -- 2.39.5