diff options
| author | Venki Pallipadi <venkatesh.pallipadi@intel.com> | 2007-06-20 14:24:00 -0700 |
|---|---|---|
| committer | Dave Jones <davej@redhat.com> | 2007-06-21 12:57:53 -0400 |
| commit | c7f652e0487a35c16f6cd72707232b6a28647a10 (patch) | |
| tree | 8ef6901d94aa0f168ae4ad07275c3cf15a0b3818 /drivers/cpufreq/cpufreq_userspace.c | |
| parent | 689eba77cbd0cfaaa3687cbe23e8b534f8ae0ebb (diff) | |
| download | linux-c7f652e0487a35c16f6cd72707232b6a28647a10.tar.bz2 | |
[CPUFREQ] Keep userspace governor quiet when it is not being used
Userspace governor registers a frequency change notifier at init time, even
when no CPU is set to userspace governor. Make it register only when
atleast one CPU is using userspace.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq_userspace.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_userspace.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c index 860345c7799a..b1348ff9fcf4 100644 --- a/drivers/cpufreq/cpufreq_userspace.c +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -37,6 +37,7 @@ static unsigned int cpu_set_freq[NR_CPUS]; /* CPU freq desired by userspace */ static unsigned int cpu_is_managed[NR_CPUS]; static DEFINE_MUTEX (userspace_mutex); +static int cpus_using_userspace_governor; #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_GOVERNOR, "userspace", msg) @@ -47,7 +48,11 @@ userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val, { struct cpufreq_freqs *freq = data; - dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n", freq->cpu, freq->new); + if (!cpu_is_managed[freq->cpu]) + return 0; + + dprintk("saving cpu_cur_freq of cpu %u to be %u kHz\n", + freq->cpu, freq->new); cpu_cur_freq[freq->cpu] = freq->new; return 0; @@ -142,6 +147,13 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy, if (rc) goto start_out; + if (cpus_using_userspace_governor == 0) { + cpufreq_register_notifier( + &userspace_cpufreq_notifier_block, + CPUFREQ_TRANSITION_NOTIFIER); + } + cpus_using_userspace_governor++; + cpu_is_managed[cpu] = 1; cpu_min_freq[cpu] = policy->min; cpu_max_freq[cpu] = policy->max; @@ -153,6 +165,13 @@ start_out: break; case CPUFREQ_GOV_STOP: mutex_lock(&userspace_mutex); + cpus_using_userspace_governor--; + if (cpus_using_userspace_governor == 0) { + cpufreq_unregister_notifier( + &userspace_cpufreq_notifier_block, + CPUFREQ_TRANSITION_NOTIFIER); + } + cpu_is_managed[cpu] = 0; cpu_min_freq[cpu] = 0; cpu_max_freq[cpu] = 0; @@ -198,7 +217,6 @@ EXPORT_SYMBOL(cpufreq_gov_userspace); static int __init cpufreq_gov_userspace_init(void) { - cpufreq_register_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); return cpufreq_register_governor(&cpufreq_gov_userspace); } @@ -206,7 +224,6 @@ static int __init cpufreq_gov_userspace_init(void) static void __exit cpufreq_gov_userspace_exit(void) { cpufreq_unregister_governor(&cpufreq_gov_userspace); - cpufreq_unregister_notifier(&userspace_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); } |