[PATCH V8 5/6] arm64/perf: Add branch stack support in ARMV8 PMU

[Will Deacon]

On Tue, Jan 31, 2023 at 12:28:17AM +0800, kernel test robot wrote:
> Hi Anshuman,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on arm64/for-next/core]
> [also build test WARNING on tip/perf/core acme/perf/core linus/master v6.2-rc6 next-20230130]
> [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#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Anshuman-Khandual/drivers-perf-arm_pmu-Add-new-sched_task-callback/20230123-210254
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
> patch link:    https://lore.kernel.org/r/20230123125956.1350336-6-anshuman.khandual%40arm.com
> patch subject: [PATCH V8 5/6] arm64/perf: Add branch stack support in ARMV8 PMU
> config: arm64-randconfig-r016-20230130 (https://download.01.org/0day-ci/archive/20230131/202301310047.b5iv9hM8-lkp@intel.com/config)
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 4196ca3278f78c6e19246e54ab0ecb364e37d66a)
> 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/intel-lab-lkp/linux/commit/0deba04ac45f8632b8579cb5cbf908b9f4428402
>         git remote add linux-review https://github.com/intel-lab-lkp/linux
>         git fetch --no-tags linux-review Anshuman-Khandual/drivers-perf-arm_pmu-Add-new-sched_task-callback/20230123-210254
>         git checkout 0deba04ac45f8632b8579cb5cbf908b9f4428402
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 prepare
> 
> If you fix the issue, kindly add following tag where applicable
> | Reported-by: kernel test robot <lkp at intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>    In file included from arch/arm64/kernel/asm-offsets.c:15:
>    In file included from include/linux/kvm_host.h:45:
>    In file included from arch/arm64/include/asm/kvm_host.h:36:
>    In file included from include/kvm/arm_pmu.h:11:
> >> arch/arm64/include/asm/perf_event.h:280:20: warning: function 'has_branch_stack' has internal linkage but is not defined [-Wundefined-internal]
>    static inline bool has_branch_stack(struct perf_event *event);
>                       ^
>    arch/arm64/include/asm/perf_event.h:284:16: note: used here
>            WARN_ON_ONCE(!has_branch_stack(event));
>                          ^
>    1 warning generated.
> --
>    In file included from arch/arm64/kernel/asm-offsets.c:15:
>    In file included from include/linux/kvm_host.h:45:
>    In file included from arch/arm64/include/asm/kvm_host.h:36:
>    In file included from include/kvm/arm_pmu.h:11:
> >> arch/arm64/include/asm/perf_event.h:280:20: warning: function 'has_branch_stack' has internal linkage but is not defined [-Wundefined-internal]
>    static inline bool has_branch_stack(struct perf_event *event);
>                       ^
>    arch/arm64/include/asm/perf_event.h:284:16: note: used here
>            WARN_ON_ONCE(!has_branch_stack(event));
>                          ^
>    1 warning generated.

This looks like it should be fixed. I'd also like to see Mark's ack on the
final series, since he had some detailed comments on the previous version.

Will