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author | Thomas Renninger <trenn@suse.de> | 2009-02-04 11:55:12 +0100 |
---|---|---|
committer | Dave Jones <davej@redhat.com> | 2009-02-24 22:47:31 -0500 |
commit | 112124ab0a9f507a0d7fdbb1e1ed2b9a24f8c4ea (patch) | |
tree | 15512b608d8f8f58817c1053d22a39d8f45e8b6d /drivers/cpufreq | |
parent | 9411b4ef7fcb534fe1582fe02738254e398dd931 (diff) | |
download | kernel_samsung_aries-112124ab0a9f507a0d7fdbb1e1ed2b9a24f8c4ea.zip kernel_samsung_aries-112124ab0a9f507a0d7fdbb1e1ed2b9a24f8c4ea.tar.gz kernel_samsung_aries-112124ab0a9f507a0d7fdbb1e1ed2b9a24f8c4ea.tar.bz2 |
[CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictions
Limit sampling rate to transition_latency * 100 or kernel limits.
If sampling_rate is tried to be set too low, set the lowest allowed value.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r-- | drivers/cpufreq/cpufreq_conservative.c | 28 | ||||
-rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 28 |
2 files changed, 36 insertions, 20 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 0912d7c..8d541c6 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -54,8 +54,20 @@ static unsigned int def_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) -#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) +#define LATENCY_MULTIPLIER (1000) #define DEF_SAMPLING_DOWN_FACTOR (1) #define MAX_SAMPLING_DOWN_FACTOR (10) #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) @@ -208,13 +220,11 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused, ret = sscanf(buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_SAMPLING_RATE || - input < MIN_SAMPLING_RATE) { + if (ret != 1) { mutex_unlock(&dbs_mutex); return -EINVAL; } - - dbs_tuners_ins.sampling_rate = input; + dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); mutex_unlock(&dbs_mutex); return count; @@ -540,11 +550,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if (latency == 0) latency = 1; - def_sampling_rate = 10 * latency * - DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; - - if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) - def_sampling_rate = MIN_STAT_SAMPLING_RATE; + def_sampling_rate = + max(10 * latency * LATENCY_MULTIPLIER, + MIN_STAT_SAMPLING_RATE); dbs_tuners_ins.sampling_rate = def_sampling_rate; diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 32ddeaa..338f428 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -52,8 +52,20 @@ static unsigned int def_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) -#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) +#define LATENCY_MULTIPLIER (1000) #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) static void do_dbs_timer(struct work_struct *work); @@ -255,13 +267,11 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused, ret = sscanf(buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_SAMPLING_RATE - || input < MIN_SAMPLING_RATE) { + if (ret != 1) { mutex_unlock(&dbs_mutex); return -EINVAL; } - - dbs_tuners_ins.sampling_rate = input; + dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); mutex_unlock(&dbs_mutex); return count; @@ -607,11 +617,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if (latency == 0) latency = 1; - def_sampling_rate = latency * - DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; - - if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) - def_sampling_rate = MIN_STAT_SAMPLING_RATE; + def_sampling_rate = + max(latency * LATENCY_MULTIPLIER, + MIN_STAT_SAMPLING_RATE); dbs_tuners_ins.sampling_rate = def_sampling_rate; } |