Hi Marcelo, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tip/timers/core] [also build test WARNING on linux/master linus/master v5.12-rc6 next-20210407] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Marcelo-Tosatti/hrtimer-avoid-retrigger_next_event-IPI/20210407-233005 base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git d4c7c28806616809e3baa0b7cd8c665516b2726d config: arm64-randconfig-r032-20210407 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project c060945b23a1c54d4b2a053ff4b093a2277b303d) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu # https://github.com/0day-ci/linux/commit/defd4db9d63d1f16e3e21862bd9c9105a9f6a7e9 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Marcelo-Tosatti/hrtimer-avoid-retrigger_next_event-IPI/20210407-233005 git checkout defd4db9d63d1f16e3e21862bd9c9105a9f6a7e9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): kernel/time/hrtimer.c:120:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:121:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, ^~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:122:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:123:17: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_TAI] = HRTIMER_BASE_TAI, ^~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ >> kernel/time/hrtimer.c:944:1: warning: unused label 'set_timerfd' [-Wunused-label] set_timerfd: ^~~~~~~~~~~~ kernel/time/hrtimer.c:147:20: warning: unused function 'is_migration_base' [-Wunused-function] static inline bool is_migration_base(struct hrtimer_clock_base *base) ^ kernel/time/hrtimer.c:650:19: warning: unused function 'hrtimer_hres_active' [-Wunused-function] static inline int hrtimer_hres_active(void) ^ kernel/time/hrtimer.c:881:13: warning: unused function 'need_reprogram_timer' [-Wunused-function] static bool need_reprogram_timer(struct hrtimer_cpu_base *cpu_base) ^ kernel/time/hrtimer.c:1793:20: warning: unused function '__hrtimer_peek_ahead_timers' [-Wunused-function] static inline void __hrtimer_peek_ahead_timers(void) { } ^ 9 warnings generated. vim +/set_timerfd +944 kernel/time/hrtimer.c 895 896 /* 897 * Clock realtime was set 898 * 899 * Change the offset of the realtime clock vs. the monotonic 900 * clock. 901 * 902 * We might have to reprogram the high resolution timer interrupt. On 903 * SMP we call the architecture specific code to retrigger _all_ high 904 * resolution timer interrupts. On UP we just disable interrupts and 905 * call the high resolution interrupt code. 906 */ 907 void clock_was_set(void) 908 { 909 #ifdef CONFIG_HIGH_RES_TIMERS 910 cpumask_var_t mask; 911 int cpu; 912 913 if (!tick_nohz_full_enabled()) { 914 /* Retrigger the CPU local events everywhere */ 915 on_each_cpu(retrigger_next_event, NULL, 1); 916 goto set_timerfd; 917 } 918 919 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) { 920 on_each_cpu(retrigger_next_event, NULL, 1); 921 goto set_timerfd; 922 } 923 924 /* Avoid interrupting nohz_full CPUs if possible */ 925 preempt_disable(); 926 for_each_online_cpu(cpu) { 927 if (tick_nohz_full_cpu(cpu)) { 928 unsigned long flags; 929 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 930 931 raw_spin_lock_irqsave(&cpu_base->lock, flags); 932 if (need_reprogram_timer(cpu_base)) 933 cpumask_set_cpu(cpu, mask); 934 else 935 hrtimer_update_base(cpu_base); 936 raw_spin_unlock_irqrestore(&cpu_base->lock, flags); 937 } 938 } 939 940 smp_call_function_many(mask, retrigger_next_event, NULL, 1); 941 preempt_enable(); 942 free_cpumask_var(mask); 943 #endif > 944 set_timerfd: 945 timerfd_clock_was_set(); 946 } 947 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org