[CPUFREQ] Resolve time unit thinko in ondemand/conservative govs

ondemand and conservative governors are messing up time units in the
code path where NO_HZ is not enabled and ignore_nice is set. The walltime
idletime stored is in jiffies and nice time calculation is happening in
microseconds.

The problem was reported and diagnosed by Alexander here.
http://marc.info/?l=linux-kernel&m=125752550404513&w=2

The patch below fixes this thinko.

Reported-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Tested-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index bc33ddc9c97cddd9e29eedc1a2737dee7e5cf5f7..c7b081b839ffe1fb37df117fb2f0395467383ec4 100644 (file)
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -116,9 +116,9 @@ static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
 
        idle_time = cputime64_sub(cur_wall_time, busy_time);
        if (wall)
-               *wall = cur_wall_time;
+               *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
 
-       return idle_time;
+       return (cputime64_t)jiffies_to_usecs(idle_time);;
 }
 
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 071699de50eef68a56e586224ccbe1d07e319011..4b34ade2332baaa50bb1ca1af9c45e1a9893d321 100644 (file)
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -133,9 +133,9 @@ static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
 
        idle_time = cputime64_sub(cur_wall_time, busy_time);
        if (wall)
-               *wall = cur_wall_time;
+               *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
 
-       return idle_time;
+       return (cputime64_t)jiffies_to_usecs(idle_time);
 }
 
 static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)