summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/cpufreq_conservative.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-17 09:51:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-17 09:51:50 -0700
commitc30938d59e7468259855da91a885b19e8044b5f4 (patch)
tree15fa3b7c4696947d43702273291398a91232f644 /drivers/cpufreq/cpufreq_conservative.c
parentaa2638a210ab0d7c6702cd54315365785fce326c (diff)
parent8e7c25971b1590776a90b249de3d859dd45e7414 (diff)
downloadlinux-c30938d59e7468259855da91a885b19e8044b5f4.tar.gz
linux-c30938d59e7468259855da91a885b19e8044b5f4.tar.bz2
linux-c30938d59e7468259855da91a885b19e8044b5f4.zip
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] cpumask: new cpumask operators for arch/x86/kernel/cpu/cpufreq/powernow-k8.c [CPUFREQ] cpumask: avoid playing with cpus_allowed in powernow-k8.c [CPUFREQ] cpumask: avoid cpumask games in arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c [CPUFREQ] cpumask: avoid playing with cpus_allowed in speedstep-ich.c [CPUFREQ] powernow-k8: get drv data for correct CPU [CPUFREQ] powernow-k8: read P-state from HW [CPUFREQ] reduce scope of ACPI_PSS_BIOS_BUG_MSG[] [CPUFREQ] Clean up convoluted code in arch/x86/kernel/tsc.c:time_cpufreq_notifier() [CPUFREQ] minor correction to cpu-freq documentation [CPUFREQ] powernow-k8.c: mess cleanup [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is useful [CPUFREQ] powernow-k8: Set transition latency to 1 if ACPI tables export 0 [CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ case
Diffstat (limited to 'drivers/cpufreq/cpufreq_conservative.c')
-rw-r--r--drivers/cpufreq/cpufreq_conservative.c61
1 files changed, 20 insertions, 41 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 7a74d175287b..7fc58af748b4 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -42,27 +42,12 @@
* this governor will not work.
* All times here are in uS.
*/
-static unsigned int def_sampling_rate;
#define MIN_SAMPLING_RATE_RATIO (2)
-/* for correct statistics, we need at least 10 ticks between each measure */
-#define MIN_STAT_SAMPLING_RATE \
- (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
-#define MIN_SAMPLING_RATE \
- (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
-/* Above MIN_SAMPLING_RATE will vanish with its sysfs file soon
- * Define the minimal settable sampling rate to the greater of:
- * - "HW transition latency" * 100 (same as default sampling / 10)
- * - MIN_STAT_SAMPLING_RATE
- * To avoid that userspace shoots itself.
-*/
-static unsigned int minimum_sampling_rate(void)
-{
- return max(def_sampling_rate / 10, MIN_STAT_SAMPLING_RATE);
-}
-/* This will also vanish soon with removing sampling_rate_max */
-#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
+static unsigned int min_sampling_rate;
+
#define LATENCY_MULTIPLIER (1000)
+#define MIN_LATENCY_MULTIPLIER (100)
#define DEF_SAMPLING_DOWN_FACTOR (1)
#define MAX_SAMPLING_DOWN_FACTOR (10)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
@@ -182,27 +167,14 @@ static struct notifier_block dbs_cpufreq_notifier_block = {
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
{
- static int print_once;
-
- if (!print_once) {
- printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
- "sysfs file is deprecated - used by: %s\n",
- current->comm);
- print_once = 1;
- }
- return sprintf(buf, "%u\n", MAX_SAMPLING_RATE);
+ printk_once(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
+ "sysfs file is deprecated - used by: %s\n", current->comm);
+ return sprintf(buf, "%u\n", -1U);
}
static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
{
- static int print_once;
-
- if (!print_once) {
- printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
- "sysfs file is deprecated - used by: %s\n", current->comm);
- print_once = 1;
- }
- return sprintf(buf, "%u\n", MIN_SAMPLING_RATE);
+ return sprintf(buf, "%u\n", min_sampling_rate);
}
#define define_one_ro(_name) \
@@ -254,7 +226,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
return -EINVAL;
mutex_lock(&dbs_mutex);
- dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate());
+ dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
mutex_unlock(&dbs_mutex);
return count;
@@ -601,11 +573,18 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
if (latency == 0)
latency = 1;
- def_sampling_rate =
- max(latency * LATENCY_MULTIPLIER,
- MIN_STAT_SAMPLING_RATE);
-
- dbs_tuners_ins.sampling_rate = def_sampling_rate;
+ /*
+ * conservative does not implement micro like ondemand
+ * governor, thus we are bound to jiffes/HZ
+ */
+ min_sampling_rate =
+ MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
+ /* Bring kernel and HW constraints together */
+ min_sampling_rate = max(min_sampling_rate,
+ MIN_LATENCY_MULTIPLIER * latency);
+ dbs_tuners_ins.sampling_rate =
+ max(min_sampling_rate,
+ latency * LATENCY_MULTIPLIER);
cpufreq_register_notifier(
&dbs_cpufreq_notifier_block,