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| author | Venki Pallipadi <venkatesh.pallipadi@intel.com> | 2007-06-20 14:24:52 -0700 |
|---|---|---|
| committer | Dave Jones <davej@redhat.com> | 2007-06-21 12:57:53 -0400 |
| commit | 0af99b13c9f323e658b4f1d69a1ccae7d6f3f80a (patch) | |
| tree | 531d6ae823c0e7facfd375106f79c213c4a1290b /drivers/cpufreq/cpufreq_ondemand.c | |
| parent | c7f652e0487a35c16f6cd72707232b6a28647a10 (diff) | |
| download | blackbird-op-linux-0af99b13c9f323e658b4f1d69a1ccae7d6f3f80a.tar.gz blackbird-op-linux-0af99b13c9f323e658b4f1d69a1ccae7d6f3f80a.zip | |
[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>
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 8532bb79e5fc..dc6f357390e2 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -325,7 +325,7 @@ static struct attribute_group dbs_attr_group = { 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 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) 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) { |
