Clean up that CONFIG_RETPOLINE crud and replace the
indirect call x86_pmu.guest_get_msrs with static_call().
Suggested-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Like Xu <[email protected]>
---
arch/x86/events/core.c | 16 ++++++++++++++++
arch/x86/events/intel/core.c | 20 --------------------
2 files changed, 16 insertions(+), 20 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index e37de298a495..2eec3c8d0a13 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -81,6 +81,8 @@ DEFINE_STATIC_CALL_NULL(x86_pmu_swap_task_ctx, *x86_pmu.swap_task_ctx);
DEFINE_STATIC_CALL_NULL(x86_pmu_drain_pebs, *x86_pmu.drain_pebs);
DEFINE_STATIC_CALL_NULL(x86_pmu_pebs_aliases, *x86_pmu.pebs_aliases);
+DEFINE_STATIC_CALL_NULL(x86_pmu_guest_get_msrs, *x86_pmu.guest_get_msrs);
+
u64 __read_mostly hw_cache_event_ids
[PERF_COUNT_HW_CACHE_MAX]
[PERF_COUNT_HW_CACHE_OP_MAX]
@@ -665,6 +667,18 @@ void x86_pmu_disable_all(void)
}
}
+struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
+{
+ struct perf_guest_switch_msr *ret = NULL;
+
+ ret = static_call(x86_pmu_guest_get_msrs)(nr);
+ if (!ret)
+ *nr = 0;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
+
/*
* There may be PMI landing after enabled=0. The PMI hitting could be before or
* after disable_all.
@@ -1923,6 +1937,8 @@ static void x86_pmu_static_call_update(void)
static_call_update(x86_pmu_drain_pebs, x86_pmu.drain_pebs);
static_call_update(x86_pmu_pebs_aliases, x86_pmu.pebs_aliases);
+
+ static_call_update(x86_pmu_guest_get_msrs, x86_pmu.guest_get_msrs);
}
static void _x86_pmu_read(struct perf_event *event)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index d4569bfa83e3..93adf53cce5f 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3680,26 +3680,6 @@ static int intel_pmu_hw_config(struct perf_event *event)
return 0;
}
-#ifdef CONFIG_RETPOLINE
-static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr);
-static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr);
-#endif
-
-struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
-{
-#ifdef CONFIG_RETPOLINE
- if (x86_pmu.guest_get_msrs == intel_guest_get_msrs)
- return intel_guest_get_msrs(nr);
- else if (x86_pmu.guest_get_msrs == core_guest_get_msrs)
- return core_guest_get_msrs(nr);
-#endif
- if (x86_pmu.guest_get_msrs)
- return x86_pmu.guest_get_msrs(nr);
- *nr = 0;
- return NULL;
-}
-EXPORT_SYMBOL_GPL(perf_guest_get_msrs);
-
static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
--
2.29.2
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 <[email protected]>
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/[email protected]
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 <[email protected]>
>
> 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/[email protected]
>
On Mon, Jan 18, 2021 at 09:05:06PM +0800, Like Xu wrote:
> I guess this fix will silence the compiler error,
> and v2 will be sent after the local 0day test passes.
I think there's also a problem where you don't assign a function at all.
I think you want something like
if (!x86_pmu.guest_get_msr)
x86_pmu.guest_get_msr = guest_get_msr_nop;
right before x86_pmu_static_call_update();
And then have it be something like:
static void *guest_et_msr_nop(int *nr)
{
*nr = 0;
return NULL;
}
and then you can reduce the entire thing to:
struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
{
return static_call(x86_pmu_guest_get_msrs)(nr);
}
On Mon, Jan 18, 2021 at 03:21:51PM +0800, Like Xu wrote:
> Clean up that CONFIG_RETPOLINE crud and replace the
> indirect call x86_pmu.guest_get_msrs with static_call().
>
> Suggested-by: Peter Zijlstra (Intel) <[email protected]>
> Signed-off-by: Like Xu <[email protected]>
Thanks!
On 2021/1/18 21:35, Peter Zijlstra wrote:
> On Mon, Jan 18, 2021 at 09:05:06PM +0800, Like Xu wrote:
>> I guess this fix will silence the compiler error,
>> and v2 will be sent after the local 0day test passes.
>
> I think there's also a problem where you don't assign a function at all.
Thank you!
>
> I think you want something like
>
> if (!x86_pmu.guest_get_msr)
> x86_pmu.guest_get_msr = guest_get_msr_nop;
>
> right before x86_pmu_static_call_update();
>
> And then have it be something like:
>
> static void *guest_et_msr_nop(int *nr)
The [-Werror=incompatible-pointer-types] will yell at "void *".
Please review the v2 version.
https://lore.kernel.org/lkml/[email protected]/T/#u
> {
> *nr = 0;
> return NULL;
> }
>
> and then you can reduce the entire thing to:
>
> struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr)
> {
> return static_call(x86_pmu_guest_get_msrs)(nr);
> }
>