Re: [PATCH] Revert "cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC"

2016-04-21 Thread Viresh Kumar 
On 21-04-16, 20:57, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki 
> 
> 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 
> Cc: 4.5+  # 4.5+
> Signed-off-by: Rafael J. Wysocki 
> ---
>  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];

Acked-by: Viresh Kumar 

-- 
viresh

Re: [PATCH] Revert "cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC"

2016-04-21 Thread Viresh Kumar 
On 21-04-16, 20:57, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki 
> 
> 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 
> Cc: 4.5+  # 4.5+
> Signed-off-by: Rafael J. Wysocki 
> ---
>  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];

Acked-by: Viresh Kumar 

-- 
viresh