cpufreq: interactive: run at fraction of hispeed_freq when load is low

When load is below go_hispeed_load, apply the percentage of CPU load to
a max frequency of hispeed_freq instead of the max speed.  This avoids
jumping too quickly to hispeed_freq when it is a relatively low
percentage of max speed.  This also allows go_hispeed_load to be set to
a high percentage relative to hispeed_freq (as a percentage of max speed,
again useful when hispeed_freq is a low fraction of max speed), to cap
larger loads at hispeed_freq.  For example, a load of 60% will typically
move to 60% of hispeed_freq, not 60% of max speed.  This causes the
governor to apply two different speed caps, depending on whether load is
below or above go_hispeed_load.

Also fix the type of hispeed_freq, which was u64, to match other
speed data types (and avoid overhead and allow division).

Change-Id: Ie2d0668be161c074aaad77db2037505431457b3a
Signed-off-by: Todd Poynor <toddpoynor@google.com>

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index f85fbbd6cb7b6efb87fe66bd4f3e5f801f47fc45..16bd23be2495bdebd46a5aff00c5df1a64524d3f 100644 (file)
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -63,7 +63,7 @@ static cpumask_t speedchange_cpumask;
 static spinlock_t speedchange_cpumask_lock;
 
 /* Hi speed to bump to from lo speed when load burst (default max) */
-static u64 hispeed_freq;
+static unsigned int hispeed_freq;
 
 /* Go to hi speed when CPU load at or above this value. */
 #define DEFAULT_GO_HISPEED_LOAD 85
@@ -198,7 +198,7 @@ static void cpufreq_interactive_timer(unsigned long data)
                        }
                }
        } else {
-               new_freq = pcpu->policy->max * cpu_load / 100;
+               new_freq = hispeed_freq * cpu_load / 100;
        }
 
        if (new_freq <= hispeed_freq)
@@ -465,7 +465,7 @@ static void cpufreq_interactive_boost(void)
 static ssize_t show_hispeed_freq(struct kobject *kobj,
                                 struct attribute *attr, char *buf)
 {
-       return sprintf(buf, "%llu\n", hispeed_freq);
+       return sprintf(buf, "%u\n", hispeed_freq);
 }
 
 static ssize_t store_hispeed_freq(struct kobject *kobj,
@@ -473,9 +473,9 @@ static ssize_t store_hispeed_freq(struct kobject *kobj,
                                  size_t count)
 {
        int ret;
-       u64 val;
+       long unsigned int val;
 
-       ret = strict_strtoull(buf, 0, &val);
+       ret = strict_strtoul(buf, 0, &val);
        if (ret < 0)
                return ret;
        hispeed_freq = val;