From: Chris Redpath Date: Mon, 17 Jun 2013 17:36:56 +0000 (+0100) Subject: cpufreq: interactive governor drops bits in time calculation X-Git-Tag: firefly_0821_release~3680^2~233^2^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1d7f81197e575c00bf5dfa988f4c7a12c45993b2;p=firefly-linux-kernel-4.4.55.git cpufreq: interactive governor drops bits in time calculation Keep time calculation in 64-bit throughout. If we have long times between idle calculations this can result in deltas > 32 bits which causes incorrect load percentage calculations and selecting the wrong frequencies if we truncate here. Signed-off-by: Chris Redpath --- diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c index 7f1782ade53c..a494fbd7dbe8 100644 --- a/drivers/cpufreq/cpufreq_interactive.c +++ b/drivers/cpufreq/cpufreq_interactive.c @@ -316,13 +316,13 @@ static u64 update_load(int cpu) pcpu->policy->governor_data; u64 now; u64 now_idle; - unsigned int delta_idle; - unsigned int delta_time; + u64 delta_idle; + u64 delta_time; u64 active_time; now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy); - delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle); - delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp); + delta_idle = (now_idle - pcpu->time_in_idle); + delta_time = (now - pcpu->time_in_idle_timestamp); if (delta_time <= delta_idle) active_time = 0;