tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2021.08.16a
head:   e376d3475154c40e5210eebbf33ac94696972190
commit: c7f73594812ddbe1d8cadb8c595dc7adcfa97e54 [70/91] EXP cpu: Make cpu_hp_check_delay() return true when detecting an anomaly
config: sparc64-buildonly-randconfig-r002-20210820 (attached as .config)
compiler: sparc64-linux-gcc (GCC) 11.2.0
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
        # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=c7f73594812ddbe1d8cadb8c595dc7adcfa97e54
        git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
        git fetch --no-tags rcu dev.2021.08.16a
        git checkout c7f73594812ddbe1d8cadb8c595dc7adcfa97e54
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sparc64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   kernel/cpu.c:137:6: error: redefinition of 'cpu_hp_start_now'
     137 | void cpu_hp_start_now(void)
         |      ^~~~~~~~~~~~~~~~
   In file included from kernel/cpu.c:17:
   include/linux/cpu.h:147:20: note: previous definition of 'cpu_hp_start_now' with type 'void(void)'
     147 | static inline void cpu_hp_start_now(void) { }
         |                    ^~~~~~~~~~~~~~~~
   kernel/cpu.c:146:6: error: redefinition of 'cpu_hp_stop_now'
     146 | void cpu_hp_stop_now(void)
         |      ^~~~~~~~~~~~~~~
   In file included from kernel/cpu.c:17:
   include/linux/cpu.h:148:20: note: previous definition of 'cpu_hp_stop_now' with type 'void(void)'
     148 | static inline void cpu_hp_stop_now(void) { }
         |                    ^~~~~~~~~~~~~~~
>> kernel/cpu.c:158:6: error: conflicting types for 'cpu_hp_check_delay'; have 'bool(const char *, const void *)' {aka '_Bool(const char *, const void *)'}
     158 | bool cpu_hp_check_delay(const char *s, const void *func)
         |      ^~~~~~~~~~~~~~~~~~
   In file included from kernel/cpu.c:17:
   include/linux/cpu.h:149:20: note: previous definition of 'cpu_hp_check_delay' with type 'bool(const char *, void *)' {aka '_Bool(const char *, void *)'}
     149 | static inline bool cpu_hp_check_delay(const char *s, void *func) { return false; }
         |                    ^~~~~~~~~~~~~~~~~~


vim +158 kernel/cpu.c

   156	
   157	/* Return true if a time-delay anomaly was detected. */
 > 158	bool cpu_hp_check_delay(const char *s, const void *func)
   159	{
   160		bool ret = false;
   161		u64 t, t1;
   162	
   163		if (!smp_load_acquire(&cpu_hp_start_time_valid))
   164			return false;
   165		t = READ_ONCE(cpu_hp_start_time);
   166		smp_mb();
   167		if (!READ_ONCE(cpu_hp_start_time_valid))
   168			return false;
   169		t1 = ktime_get();
   170		if (WARN_ONCE(time_after64(t1, t + 100 * NSEC_PER_SEC), "%s %ps took %llu milliseconds\n", s, func, (t1 - t) / NSEC_PER_MSEC)) {
   171			WRITE_ONCE(cpu_hp_start_time, t1);
   172			ret = true;
   173		}
   174		if (WARN_ONCE(time_before64(t1, t - 25 * NSEC_PER_MSEC), "%s %ps clock went backwards %llu milliseconds\n", s, func, (t - t1) / NSEC_PER_MSEC)){
   175			WRITE_ONCE(cpu_hp_start_time, t1);
   176			ret = true;
   177		}
   178		return ret;
   179	}
   180	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org