From: Venki Pallipadi Date: Wed, 20 Jun 2007 21:24:52 +0000 (-0700) Subject: CPUFREQ: ondemand: add a check to avoid negative load calculation X-Git-Tag: v2.6.22.3~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=72a63b079035709b481edffa301c4a694e008384;p=people%2Fms%2Flinux.git 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 Signed-off-by: Dave Jones Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index b6b3e52c9f28..e794527e4925 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -335,7 +335,7 @@ 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; @@ -381,7 +381,8 @@ 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) {