Re: [RFC PATCH 3/5] tracing/hwlat: Implement the per-cpu mode

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

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Hi Daniel,

[FYI, it's a private test report for your RFC patch.]
[auto build test ERROR on tip/perf/core]
[also build test ERROR on linux/master linus/master v5.12-rc6]
[cannot apply to trace/for-next next-20210408]
[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/Daniel-Bristot-de-Oliveira/hwlat-improvements-and-osnoise-tracer/20210408-221655
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git cface0326a6c2ae5c8f47bd466f07624b3e348a7
config: mips-randconfig-r002-20210408 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 56ea2e2fdd691136d5e6631fa0e447173694b82c)
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 mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/4e2f5d30c69f77756e8cf223acf55c2aa2657393
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Daniel-Bristot-de-Oliveira/hwlat-improvements-and-osnoise-tracer/20210408-221655
        git checkout 4e2f5d30c69f77756e8cf223acf55c2aa2657393
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

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/trace/trace_hwlat.c:122:28: warning: no previous prototype for function 'get_cpu_data' [-Wmissing-prototypes]
   struct hwlat_kthread_data *get_cpu_data(void)
                              ^
   kernel/trace/trace_hwlat.c:122:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct hwlat_kthread_data *get_cpu_data(void)
   ^
   static 
>> kernel/trace/trace_hwlat.c:496:25: error: incompatible pointer types passing 'struct cpumask **' to parameter of type 'cpumask_var_t *' (aka 'struct cpumask (*)[1]') [-Werror,-Wincompatible-pointer-types]
           if (!alloc_cpumask_var(&this_cpumask, GFP_KERNEL))
                                  ^~~~~~~~~~~~~
   include/linux/cpumask.h:767:53: note: passing argument to parameter 'mask' here
   static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
                                                       ^
   1 warning and 1 error generated.


vim +496 kernel/trace/trace_hwlat.c

   480	
   481	/**
   482	 * start_per_cpu_kthread - Kick off the hardware latency sampling/detector kthreads
   483	 *
   484	 * This starts the kernel threads that will sit on potentially all cpus and
   485	 * sample the CPU timestamp counter (TSC or similar) and look for potential
   486	 * hardware latencies.
   487	 */
   488	static int start_per_cpu_kthreads(struct trace_array *tr)
   489	{
   490		struct cpumask *current_mask = &save_cpumask;
   491		struct cpumask *this_cpumask;
   492		struct task_struct *kthread;
   493		char comm[24];
   494		int cpu;
   495	
 > 496		if (!alloc_cpumask_var(&this_cpumask, GFP_KERNEL))
   497			return -ENOMEM;
   498	
   499		get_online_cpus();
   500		/*
   501		 * Run only on CPUs in which trace and hwlat are allowed to run.
   502		 */
   503		cpumask_and(current_mask, tr->tracing_cpumask, &hwlat_cpumask);
   504		/*
   505		 * And the CPU is online.
   506		 */
   507		cpumask_and(current_mask, cpu_online_mask, current_mask);
   508		put_online_cpus();
   509	
   510		for_each_online_cpu(cpu)
   511			per_cpu(hwlat_per_cpu_data, cpu).kthread = NULL;
   512	
   513		for_each_cpu(cpu, current_mask) {
   514			snprintf(comm, 24, "hwlatd/%d", cpu);
   515	
   516			kthread = kthread_create_on_cpu(kthread_fn, NULL, cpu, comm);
   517			if (IS_ERR(kthread)) {
   518				pr_err(BANNER "could not start sampling thread\n");
   519				stop_per_cpu_kthreads();
   520				return -ENOMEM;
   521			}
   522	
   523			per_cpu(hwlat_per_cpu_data, cpu).kthread = kthread;
   524			wake_up_process(kthread);
   525		}
   526	
   527		return 0;
   528	}
   529	

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

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