From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Revert commit 0df35026c6a5 (cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC) that introduced a regression by causing the ondemand cpufreq governor to misbehave for CONFIG_TICK_CPU_ACCOUNTING unset (the frequency goes up to the max at one point and stays there indefinitely).
The revert takes subsequent modifications of the code in question into account. Fixes: 0df35026c6a5 (cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC) Link: https://bugzilla.kernel.org/show_bug.cgi?id=115261 Reported-and-tested-by: Timo Valtoaho <timo.valto...@gmail.com> Cc: 4.5+ <sta...@vger.kernel.org> # 4.5+ Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com> --- drivers/cpufreq/cpufreq_governor.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) Index: linux-pm/drivers/cpufreq/cpufreq_governor.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c +++ linux-pm/drivers/cpufreq/cpufreq_governor.c @@ -146,12 +146,8 @@ unsigned int dbs_update(struct cpufreq_p wall_time = cur_wall_time - j_cdbs->prev_cpu_wall; j_cdbs->prev_cpu_wall = cur_wall_time; - if (cur_idle_time <= j_cdbs->prev_cpu_idle) { - idle_time = 0; - } else { - idle_time = cur_idle_time - j_cdbs->prev_cpu_idle; - j_cdbs->prev_cpu_idle = cur_idle_time; - } + idle_time = cur_idle_time - j_cdbs->prev_cpu_idle; + j_cdbs->prev_cpu_idle = cur_idle_time; if (ignore_nice) { u64 cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
