tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git bleeding-edge
head:   7e9b0371ed5b9bf9a80c59487f47fca0ba638f61
commit: b0d640cf14148cbce9f1651fe6028c7586291cf5 [172/186] cpufreq: ondemand: Simplify idle cputime granularity test
config: x86_64-allnoconfig (https://download.01.org/0day-ci/archive/20260124/202601240833.jYdOreP4-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260124/202601240833.jYdOreP4-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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202601240833.jYdOreP4-lkp@intel.com/ (local)

All errors (new ones prefixed by >>):

quoted

kernel/time/hrtimer.c:946:41: error: call to undeclared function 'tick_nohz_is_active'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]

     946 |         if (!hrtimer_hres_active(cpu_base) && !tick_nohz_is_active())
         |                                                ^
   1 error generated.


vim +/tick_nohz_is_active +946 kernel/time/hrtimer.c

   925	
   926	/*
   927	 * Clock was set. This might affect CLOCK_REALTIME, CLOCK_TAI and
   928	 * CLOCK_BOOTTIME (for late sleep time injection).
   929	 *
   930	 * This requires to update the offsets for these clocks
   931	 * vs. CLOCK_MONOTONIC. When high resolution timers are enabled, then this
   932	 * also requires to eventually reprogram the per CPU clock event devices
   933	 * when the change moves an affected timer ahead of the first expiring
   934	 * timer on that CPU. Obviously remote per CPU clock event devices cannot
   935	 * be reprogrammed. The other reason why an IPI has to be sent is when the
   936	 * system is in !HIGH_RES and NOHZ mode. The NOHZ mode updates the offsets
   937	 * in the tick, which obviously might be stopped, so this has to bring out
   938	 * the remote CPU which might sleep in idle to get this sorted.
   939	 */
   940	void clock_was_set(unsigned int bases)
   941	{
   942		struct hrtimer_cpu_base *cpu_base = raw_cpu_ptr(&hrtimer_bases);
   943		cpumask_var_t mask;
   944		int cpu;
   945	
 > 946		if (!hrtimer_hres_active(cpu_base) && !tick_nohz_is_active())
   947			goto out_timerfd;
   948	
   949		if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {
   950			on_each_cpu(retrigger_next_event, NULL, 1);
   951			goto out_timerfd;
   952		}
   953	
   954		/* Avoid interrupting CPUs if possible */
   955		cpus_read_lock();
   956		for_each_online_cpu(cpu) {
   957			unsigned long flags;
   958	
   959			cpu_base = &per_cpu(hrtimer_bases, cpu);
   960			raw_spin_lock_irqsave(&cpu_base->lock, flags);
   961	
   962			if (update_needs_ipi(cpu_base, bases))
   963				cpumask_set_cpu(cpu, mask);
   964	
   965			raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
   966		}
   967	
   968		preempt_disable();
   969		smp_call_function_many(mask, retrigger_next_event, NULL, 1);
   970		preempt_enable();
   971		cpus_read_unlock();
   972		free_cpumask_var(mask);
   973	
   974	out_timerfd:
   975		timerfd_clock_was_set();
   976	}
   977	

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