Re: [rafael-pm:bleeding-edge 175/176] ERROR: modpost: "tick_nohz_enabled" [drivers/cpufreq/cpufreq_ondemand.ko] undefined!

["Rafael J. Wysocki" <rafael@kernel.org>]

On Friday, January 23, 2026 2:56:08 PM CET Frederic Weisbecker wrote:
> Le Fri, Jan 23, 2026 at 03:37:07PM +0800, kernel test robot a écrit :
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge
> > head:   8a22b02a1427ff0eab01a1b7cd62355238ba3d5b
> > commit: cc85c350babcb86c65da5393532f1cb255c750bc [175/176] cpufreq: ondemand: Simplify idle cputime granularity test
> > config: i386-buildonly-randconfig-002-20260123 (https://download.01.org/0day-ci/archive/20260123/202601231505.4Q8tb33s-lkp@intel.com/config)
> > compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260123/202601231505.4Q8tb33s-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202601231505.4Q8tb33s-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>, old ones prefixed by <<):
> > 
> > >> ERROR: modpost: "tick_nohz_enabled" [drivers/cpufreq/cpufreq_ondemand.ko] undefined!
> > 
> 
> Right...
> 
> Is it better with this replacement?

It is still failing the build.

I'll fix it up tomorrow.

> ---
> From: Frederic Weisbecker <frederic@kernel.org>
> Date: Wed, 7 Jan 2026 17:25:09 +0100
> Subject: [PATCH] cpufreq: ondemand: Simplify idle cputime granularity test
> 
> cpufreq calls get_cpu_idle_time_us() just to know if idle cputime
> accounting has a nanoseconds granularity.
> 
> Use the appropriate indicator instead to make that deduction.
> 
> Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: linux-pm@vger.kernel.org
> ---
>  drivers/cpufreq/cpufreq_ondemand.c | 7 +------
>  include/linux/tick.h               | 1 +
>  kernel/time/hrtimer.c              | 2 +-
>  kernel/time/tick-internal.h        | 2 --
>  kernel/time/tick-sched.c           | 8 +++++++-
>  kernel/time/timer.c                | 2 +-
>  6 files changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
> index a6ecc203f7b7..bb7db82930e4 100644
> --- a/drivers/cpufreq/cpufreq_ondemand.c
> +++ b/drivers/cpufreq/cpufreq_ondemand.c
> @@ -334,17 +334,12 @@ static void od_free(struct policy_dbs_info *policy_dbs)
>  static int od_init(struct dbs_data *dbs_data)
>  {
>  	struct od_dbs_tuners *tuners;
> -	u64 idle_time;
> -	int cpu;
>  
>  	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
>  	if (!tuners)
>  		return -ENOMEM;
>  
> -	cpu = get_cpu();
> -	idle_time = get_cpu_idle_time_us(cpu, NULL);
> -	put_cpu();
> -	if (idle_time != -1ULL) {
> +	if (tick_nohz_is_active()) {
>  		/* Idle micro accounting is supported. Use finer thresholds */
>  		dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
>  	} else {
> diff --git a/include/linux/tick.h b/include/linux/tick.h
> index ac76ae9fa36d..fe7f51451ba1 100644
> --- a/include/linux/tick.h
> +++ b/include/linux/tick.h
> @@ -126,6 +126,7 @@ enum tick_dep_bits {
>  
>  #ifdef CONFIG_NO_HZ_COMMON
>  extern bool tick_nohz_enabled;
> +extern bool tick_nohz_is_active(void);
>  extern bool tick_nohz_tick_stopped(void);
>  extern bool tick_nohz_tick_stopped_cpu(int cpu);
>  extern void tick_nohz_idle_stop_tick(void);
> diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
> index f8ea8c8fc895..e1bbf883dfa8 100644
> --- a/kernel/time/hrtimer.c
> +++ b/kernel/time/hrtimer.c
> @@ -943,7 +943,7 @@ void clock_was_set(unsigned int bases)
>  	cpumask_var_t mask;
>  	int cpu;
>  
> -	if (!hrtimer_hres_active(cpu_base) && !tick_nohz_active)
> +	if (!hrtimer_hres_active(cpu_base) && !tick_nohz_is_active())
>  		goto out_timerfd;
>  
>  	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
> diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
> index 4e4f7bbe2a64..597d816d22e8 100644
> --- a/kernel/time/tick-internal.h
> +++ b/kernel/time/tick-internal.h
> @@ -156,7 +156,6 @@ static inline void tick_nohz_init(void) { }
>  #endif
>  
>  #ifdef CONFIG_NO_HZ_COMMON
> -extern unsigned long tick_nohz_active;
>  extern void timers_update_nohz(void);
>  extern u64 get_jiffies_update(unsigned long *basej);
>  # ifdef CONFIG_SMP
> @@ -171,7 +170,6 @@ extern void timer_expire_remote(unsigned int cpu);
>  # endif
>  #else /* CONFIG_NO_HZ_COMMON */
>  static inline void timers_update_nohz(void) { }
> -#define tick_nohz_active (0)
>  #endif
>  
>  DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> index 21ac561a8545..81c619bf662c 100644
> --- a/kernel/time/tick-sched.c
> +++ b/kernel/time/tick-sched.c
> @@ -691,7 +691,7 @@ void __init tick_nohz_init(void)
>   * NO HZ enabled ?
>   */
>  bool tick_nohz_enabled __read_mostly  = true;
> -unsigned long tick_nohz_active  __read_mostly;
> +static unsigned long tick_nohz_active  __read_mostly;
>  /*
>   * Enable / Disable tickless mode
>   */
> @@ -702,6 +702,12 @@ static int __init setup_tick_nohz(char *str)
>  
>  __setup("nohz=", setup_tick_nohz);
>  
> +bool tick_nohz_is_active(void)
> +{
> +	return tick_nohz_active;
> +}
> +EXPORT_SYMBOL_GPL(tick_nohz_is_active);
> +
>  bool tick_nohz_tick_stopped(void)
>  {
>  	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
> diff --git a/kernel/time/timer.c b/kernel/time/timer.c
> index 1f2364126894..7e1e3bde6b8b 100644
> --- a/kernel/time/timer.c
> +++ b/kernel/time/timer.c
> @@ -281,7 +281,7 @@ DEFINE_STATIC_KEY_FALSE(timers_migration_enabled);
>  
>  static void timers_update_migration(void)
>  {
> -	if (sysctl_timer_migration && tick_nohz_active)
> +	if (sysctl_timer_migration && tick_nohz_is_active())
>  		static_branch_enable(&timers_migration_enabled);
>  	else
>  		static_branch_disable(&timers_migration_enabled);
>