Re: [PATCH] x86/perf: Use static_call for x86_pmu.guest_get_msrs

From: Like Xu
Date: Mon Jan 18 2021 - 08:07:44 EST


I guess this fix will silence the compiler error,
and v2 will be sent after the local 0day test passes.

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index b9a7fd0a27e2..517f546b6b45 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -479,15 +479,11 @@ static inline void perf_events_lapic_init(void) { }
static inline void perf_check_microcode(void) { }
#endif

-#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr);
+
+#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
extern int x86_perf_get_lbr(struct x86_pmu_lbr *lbr);
#else
-static inline struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
-{
- *nr = 0;
- return NULL;
-}
static inline int x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
{
return -1;

On 2021/1/18 20:12, kernel test robot wrote:
Hi Like,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/perf/core]
[also build test ERROR on v5.11-rc4 next-20210118]
[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/Like-Xu/x86-perf-Use-static_call-for-x86_pmu-guest_get_msrs/20210118-153219
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 9a7832ce3d920426a36cdd78eda4b3568d4d09e3
config: x86_64-randconfig-a002-20210118 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 95d146182fdf2315e74943b93fb3bb0cbafc5d89)
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 x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# https://github.com/0day-ci/linux/commit/0cd2262fad043a5edef91fca07d16759703658b8
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Like-Xu/x86-perf-Use-static_call-for-x86_pmu-guest_get_msrs/20210118-153219
git checkout 0cd2262fad043a5edef91fca07d16759703658b8
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64

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/x86/events/core.c:670:31: error: redefinition of 'perf_guest_get_msrs'
struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
^
arch/x86/include/asm/perf_event.h:486:45: note: previous definition is here
static inline struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
^
1 error generated.


vim +/perf_guest_get_msrs +670 arch/x86/events/core.c

669
> 670 struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
671 {
672 struct perf_guest_switch_msr *ret = NULL;
673
674 ret = static_call(x86_pmu_guest_get_msrs)(nr);
675 if (!ret)
676 *nr = 0;
677
678 return ret;
679 }
680 EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
681

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