arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters'

From: kernel test robot
Date: Fri Mar 26 2021 - 08:28:30 EST


Hi Marc,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: db24726bfefa68c606947a86132591568a06bfb4
commit: 6b5b368fccd7109b052e45af8ba1464c8d140a49 KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
date: 3 weeks ago
config: arm64-randconfig-r005-20210326 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project f490a5969bd52c8a48586f134ff8f02ccbb295b3)
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://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b5b368fccd7109b052e45af8ba1464c8d140a49
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 6b5b368fccd7109b052e45af8ba1464c8d140a49
# 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 <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

>> arch/arm64/kvm/perf.c:58:36: error: implicit declaration of function 'perf_num_counters' [-Werror,-Wimplicit-function-declaration]
if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
^
1 error generated.


vim +/perf_num_counters +58 arch/arm64/kvm/perf.c

50
51 int kvm_perf_init(void)
52 {
53 /*
54 * Check if HW_PERF_EVENTS are supported by checking the number of
55 * hardware performance counters. This could ensure the presence of
56 * a physical PMU and CONFIG_PERF_EVENT is selected.
57 */
> 58 if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0)
59 static_branch_enable(&kvm_arm_pmu_available);
60
61 return perf_register_guest_info_callbacks(&kvm_guest_cbs);
62 }
63

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

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