The patch below does not apply to the 4.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 94862a62dfe3ba1c7601115a2dc80721c5b256f0 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Date: Thu, 21 Apr 2016 20:57:47 +0200 Subject: [PATCH] Revert "cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC" 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.valtoaho@xxxxxxxxx> Cc: 4.5+ <stable@xxxxxxxxxxxxxxx> # 4.5+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c index 10a5cfeae8c5..5f1147fa9239 100644 --- a/drivers/cpufreq/cpufreq_governor.c +++ b/drivers/cpufreq/cpufreq_governor.c @@ -193,12 +193,8 @@ unsigned int dbs_update(struct cpufreq_policy *policy) 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]; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html