[CPUFREQ] ondemand: add a check to avoid negative load calculation
Due to rounding and inexact jiffy accounting, idle_ticks can sometimes
be higher than total_ticks. Make sure those cases are handled as
zero load case.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 8532bb7..dc6f357 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -325,7 +325,7 @@
static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
unsigned int idle_ticks, total_ticks;
- unsigned int load;
+ unsigned int load = 0;
cputime64_t cur_jiffies;
struct cpufreq_policy *policy;
@@ -370,7 +370,8 @@
if (tmp_idle_ticks < idle_ticks)
idle_ticks = tmp_idle_ticks;
}
- load = (100 * (total_ticks - idle_ticks)) / total_ticks;
+ if (likely(total_ticks > idle_ticks))
+ load = (100 * (total_ticks - idle_ticks)) / total_ticks;
/* Check for frequency increase */
if (load > dbs_tuners_ins.up_threshold) {