[paulmck-rcu:dev.2022.01.04a 52/55] kernel/stop_machine.c:207:6: warning: variable 't' set but not used

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2022.01.04a
head:   64595d0dff992756e8c6d53c0e9f1e3e50c451f7
commit: 5cd99ef59351bcdd73ce5412934fda67d0ca2a1c [52/55] EXP timers: NMI stacktraces for last-resort jiffies update
config: s390-randconfig-r026-20220107 (https://download.01.org/0day-ci/archive/20220108/202201082041.wv0NluSe-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 32167bfe64a4c5dd4eb3f7a58e24f4cba76f5ac2)
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 s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=5cd99ef59351bcdd73ce5412934fda67d0ca2a1c
        git remote add paulmck-rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
        git fetch --no-tags paulmck-rcu dev.2022.01.04a
        git checkout 5cd99ef59351bcdd73ce5412934fda67d0ca2a1c
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash

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

All warnings (new ones prefixed by >>):

>> kernel/stop_machine.c:207:6: warning: variable 't' set but not used [-Wunused-but-set-variable]
           u64 t;
               ^
   1 warning generated.


vim +/t +207 kernel/stop_machine.c

   201	
   202	static void dump_multi_cpu_stop_state(struct multi_stop_data *msdata, bool *firsttime)
   203	{
   204		struct cpu_stopper *stopper;
   205		unsigned long flags;
   206		int cpu;
 > 207		u64 t;
   208	
   209		tick_setup_sched_timer_dump();
   210		pr_info("%s threads %d/%d state %d\n", __func__, atomic_read(&msdata->thread_ack), msdata->num_threads, msdata->state);
   211		for_each_online_cpu(cpu) {
   212			if (cpu_is_offline(cpu))
   213				continue;
   214			stopper = &per_cpu(cpu_stopper, cpu);
   215			raw_spin_lock_irqsave(&stopper->lock, flags);
   216			t = ktime_get();
   217	//		tlast = stopper->lasttime;
   218			pr_info("%s: %s%s ->state=%#x%s\n", __func__, stopper->thread->comm, stopper->thread == current ? " (me)" : "", stopper->thread->__state, task_curr(stopper->thread) ? "" : " Not running!");
   219			raw_spin_unlock_irqrestore(&stopper->lock, flags);
   220			if (firsttime && *firsttime && !task_curr(stopper->thread)) {
   221				trigger_single_cpu_backtrace(cpu);
   222				*firsttime = false;
   223			}
   224	//		if (time_after64(t, tlast + NSEC_PER_SEC) &&
   225	//		    smp_load_acquire(&multi_stop_cpu_ipi_handled)) {
   226	//			pr_info("%s: sending IPI from CPU %d to CPU %d\n", __func__, raw_smp_processor_id(), cpu);
   227	//			WRITE_ONCE(multi_stop_cpu_ipi_handled, false);
   228	//			smp_mb();
   229	//			smp_call_function_single(cpu, multi_stop_cpu_ipi, NULL, 0);
   230	//		}
   231		}
   232	}
   233	

---
0-DAY CI Kernel Test Service, Intel Corporation
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