diff mbox series

[RFV,v2,08/13] perf/core: Add new function perf_event_topdown_metrics()

Message ID 20230808063111.1870070-9-dapeng1.mi@linux.intel.com
State New
Headers
Series Enable fixed counter 3 and topdown perf metrics for vPMU |

Commit Message

Mi, Dapeng Aug. 8, 2023, 6:31 a.m. UTC 
  Add a new function perf_event_topdown_metrics(). This new function is
quite familiar with function perf_event_period(), but it updates slots
count and metrics raw data instead of sample period into perf system.

When guest restores FIXED_CTR3 and PERF_METRICS MSRs in sched-in process,
KVM needs to capture the MSR writing trap and set the MSR values of guest
into corresponding perf events just like function perf_event_period()
does.

Initially we tried to reuse the function perf_event_period() to set the
slots/metrics value, but we found it was quite hard. The function
perf_event_period() only works on sampling events but unfortunately
slots event and metric events in topdown mode are all non-sampling
events. There are sampling event check and lots of sampling period
related check and setting in the function perf_event_period()
call-chain. If we want to reuse the function perf_event_period(), we
have to add lots of if-else changes on the entire function-chain and
even modify the function name. This would totally mess up the function
perf_event_period().

Thus, we select to create a new function perf_event_topdown_metrics() to
set the slots/metrics values. This makes logic and code both be clearer.

Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
 include/linux/perf_event.h | 13 ++++++++
 kernel/events/core.c       | 62 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

Comments

kernel test robot Aug. 8, 2023, 8:16 p.m. UTC | #1 
Hi Dapeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20230808]
[cannot apply to kvm/queue acme/perf/core tip/perf/core kvm/linux-next v6.5-rc5 v6.5-rc4 v6.5-rc3 linus/master v6.5-rc5]
[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/Dapeng-Mi/KVM-x86-pmu-Support-PMU-fixed-counter-3/20230809-030457
base:   next-20230808
patch link:    https://lore.kernel.org/r/20230808063111.1870070-9-dapeng1.mi%40linux.intel.com
patch subject: [PATCH RFV v2 08/13] perf/core: Add new function perf_event_topdown_metrics()
config: loongarch-allnoconfig (https://download.01.org/0day-ci/archive/20230809/202308090447.HY139um6-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230809/202308090447.HY139um6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308090447.HY139um6-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/trace_events.h:10,
                    from include/trace/syscall.h:7,
                    from include/linux/syscalls.h:90,
                    from arch/loongarch/mm/cache.c:17:
>> include/linux/perf_event.h:1793:53: warning: 'struct td_metrics' declared inside parameter list will not be visible outside of this definition or declaration
    1793 |                                              struct td_metrics *value)
         |                                                     ^~~~~~~~~~
--
   In file included from include/linux/trace_events.h:10,
                    from include/trace/syscall.h:7,
                    from include/linux/syscalls.h:90,
                    from include/linux/entry-common.h:7,
                    from arch/loongarch/mm/fault.c:13:
>> include/linux/perf_event.h:1793:53: warning: 'struct td_metrics' declared inside parameter list will not be visible outside of this definition or declaration
    1793 |                                              struct td_metrics *value)
         |                                                     ^~~~~~~~~~
   arch/loongarch/mm/fault.c:256:27: warning: no previous prototype for 'do_page_fault' [-Wmissing-prototypes]
     256 | asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
         |                           ^~~~~~~~~~~~~


vim +1793 include/linux/perf_event.h

  1791	
  1792	static inline int perf_event_topdown_metrics(struct perf_event *event,
> 1793						     struct td_metrics *value)
  1794	{
  1795		return 0;
  1796	}
  1797	#endif
  1798
kernel test robot Aug. 8, 2023, 8:16 p.m. UTC | #2 
Hi Dapeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20230808]
[cannot apply to kvm/queue acme/perf/core tip/perf/core kvm/linux-next v6.5-rc5 v6.5-rc4 v6.5-rc3 linus/master v6.5-rc5]
[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/Dapeng-Mi/KVM-x86-pmu-Support-PMU-fixed-counter-3/20230809-030457
base:   next-20230808
patch link:    https://lore.kernel.org/r/20230808063111.1870070-9-dapeng1.mi%40linux.intel.com
patch subject: [PATCH RFV v2 08/13] perf/core: Add new function perf_event_topdown_metrics()
config: arm-randconfig-r046-20230808 (https://download.01.org/0day-ci/archive/20230809/202308090418.vTakFy6e-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce: (https://download.01.org/0day-ci/archive/20230809/202308090418.vTakFy6e-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308090418.vTakFy6e-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from kernel/sched/build_policy.c:34:
   In file included from kernel/sched/sched.h:61:
   In file included from include/linux/syscalls_api.h:1:
   In file included from include/linux/syscalls.h:90:
   In file included from include/trace/syscall.h:7:
   In file included from include/linux/trace_events.h:10:
>> include/linux/perf_event.h:1793:18: warning: declaration of 'struct td_metrics' will not be visible outside of this function [-Wvisibility]
                                                struct td_metrics *value)
                                                       ^
   1 warning generated.
--
   In file included from kernel/sched/fair.c:56:
   In file included from kernel/sched/sched.h:61:
   In file included from include/linux/syscalls_api.h:1:
   In file included from include/linux/syscalls.h:90:
   In file included from include/trace/syscall.h:7:
   In file included from include/linux/trace_events.h:10:
>> include/linux/perf_event.h:1793:18: warning: declaration of 'struct td_metrics' will not be visible outside of this function [-Wvisibility]
                                                struct td_metrics *value)
                                                       ^
   kernel/sched/fair.c:702:6: warning: no previous prototype for function 'update_entity_lag' [-Wmissing-prototypes]
   void update_entity_lag(struct cfs_rq *cfs_rq, struct sched_entity *se)
        ^
   kernel/sched/fair.c:702:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void update_entity_lag(struct cfs_rq *cfs_rq, struct sched_entity *se)
   ^
   static 
   kernel/sched/fair.c:12732:6: warning: no previous prototype for function 'free_fair_sched_group' [-Wmissing-prototypes]
   void free_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:12732:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void free_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:12734:5: warning: no previous prototype for function 'alloc_fair_sched_group' [-Wmissing-prototypes]
   int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
       ^
   kernel/sched/fair.c:12734:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
   ^
   static 
   kernel/sched/fair.c:12739:6: warning: no previous prototype for function 'online_fair_sched_group' [-Wmissing-prototypes]
   void online_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:12739:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void online_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:12741:6: warning: no previous prototype for function 'unregister_fair_sched_group' [-Wmissing-prototypes]
   void unregister_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:12741:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void unregister_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:503:20: warning: unused function 'list_del_leaf_cfs_rq' [-Wunused-function]
   static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
                      ^
   kernel/sched/fair.c:524:19: warning: unused function 'tg_is_idle' [-Wunused-function]
   static inline int tg_is_idle(struct task_group *tg)
                     ^
   kernel/sched/fair.c:548:19: warning: unused function 'max_vruntime' [-Wunused-function]
   static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
                     ^
   kernel/sched/fair.c:1262:20: warning: unused function 'is_core_idle' [-Wunused-function]
   static inline bool is_core_idle(int cpu)
                      ^
   kernel/sched/fair.c:3452:20: warning: unused function 'account_numa_enqueue' [-Wunused-function]
   static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p)
                      ^
   kernel/sched/fair.c:3456:20: warning: unused function 'account_numa_dequeue' [-Wunused-function]
   static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
                      ^
   kernel/sched/fair.c:3460:20: warning: unused function 'update_scan_period' [-Wunused-function]
   static inline void update_scan_period(struct task_struct *p, int new_cpu)
                      ^
   kernel/sched/fair.c:4872:20: warning: unused function 'cfs_rq_is_decayed' [-Wunused-function]
   static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
                      ^
   kernel/sched/fair.c:4887:20: warning: unused function 'remove_entity_load_avg' [-Wunused-function]
   static inline void remove_entity_load_avg(struct sched_entity *se) {}
                      ^
   kernel/sched/fair.c:6259:20: warning: unused function 'cfs_bandwidth_used' [-Wunused-function]
   static inline bool cfs_bandwidth_used(void)
                      ^
   kernel/sched/fair.c:6267:20: warning: unused function 'sync_throttle' [-Wunused-function]
   static inline void sync_throttle(struct task_group *tg, int cpu) {}
                      ^
   kernel/sched/fair.c:6280:19: warning: unused function 'throttled_lb_pair' [-Wunused-function]
   static inline int throttled_lb_pair(struct task_group *tg,
                     ^
   kernel/sched/fair.c:6291:37: warning: unused function 'tg_cfs_bandwidth' [-Wunused-function]
   static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
                                       ^
   kernel/sched/fair.c:6295:20: warning: unused function 'destroy_cfs_bandwidth' [-Wunused-function]
   static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
                      ^
   kernel/sched/fair.c:6296:20: warning: unused function 'update_runtime_enabled' [-Wunused-function]
   static inline void update_runtime_enabled(struct rq *rq) {}
                      ^
   kernel/sched/fair.c:6297:20: warning: unused function 'unthrottle_offline_cfs_rqs' [-Wunused-function]
   static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {}
                      ^
   22 warnings generated.
--
   In file included from kernel/sched/core.c:13:
   In file included from include/linux/syscalls_api.h:1:
   In file included from include/linux/syscalls.h:90:
   In file included from include/trace/syscall.h:7:
   In file included from include/linux/trace_events.h:10:
>> include/linux/perf_event.h:1793:18: warning: declaration of 'struct td_metrics' will not be visible outside of this function [-Wvisibility]
                                                struct td_metrics *value)
                                                       ^
   kernel/sched/core.c:3695:20: warning: unused function 'rq_has_pinned_tasks' [-Wunused-function]
   static inline bool rq_has_pinned_tasks(struct rq *rq)
                      ^
   kernel/sched/core.c:5822:20: warning: unused function 'sched_tick_start' [-Wunused-function]
   static inline void sched_tick_start(int cpu) { }
                      ^
   kernel/sched/core.c:5823:20: warning: unused function 'sched_tick_stop' [-Wunused-function]
   static inline void sched_tick_stop(int cpu) { }
                      ^
   kernel/sched/core.c:6523:20: warning: unused function 'sched_core_cpu_starting' [-Wunused-function]
   static inline void sched_core_cpu_starting(unsigned int cpu) {}
                      ^
   kernel/sched/core.c:6524:20: warning: unused function 'sched_core_cpu_deactivate' [-Wunused-function]
   static inline void sched_core_cpu_deactivate(unsigned int cpu) {}
                      ^
   kernel/sched/core.c:6525:20: warning: unused function 'sched_core_cpu_dying' [-Wunused-function]
   static inline void sched_core_cpu_dying(unsigned int cpu) {}
                      ^
   7 warnings generated.


vim +1793 include/linux/perf_event.h

  1791	
  1792	static inline int perf_event_topdown_metrics(struct perf_event *event,
> 1793						     struct td_metrics *value)
  1794	{
  1795		return 0;
  1796	}
  1797	#endif
  1798
diff mbox series

Patch

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e95152531f4c..fe12a2ea10d9 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1661,6 +1661,11 @@  perf_event_addr_filters(struct perf_event *event)
 	return ifh;
 }
 
+struct td_metrics {
+	u64	slots;
+	u64	metric;
+};
+
 extern void perf_event_addr_filters_sync(struct perf_event *event);
 extern void perf_report_aux_output_id(struct perf_event *event, u64 hw_id);
 
@@ -1695,6 +1700,8 @@  extern void perf_event_task_tick(void);
 extern int perf_event_account_interrupt(struct perf_event *event);
 extern int perf_event_period(struct perf_event *event, u64 value);
 extern u64 perf_event_pause(struct perf_event *event, bool reset);
+extern int perf_event_topdown_metrics(struct perf_event *event,
+				      struct td_metrics *value);
 #else /* !CONFIG_PERF_EVENTS: */
 static inline void *
 perf_aux_output_begin(struct perf_output_handle *handle,
@@ -1781,6 +1788,12 @@  static inline u64 perf_event_pause(struct perf_event *event, bool reset)
 {
 	return 0;
 }
+
+static inline int perf_event_topdown_metrics(struct perf_event *event,
+					     struct td_metrics *value)
+{
+	return 0;
+}
 #endif
 
 #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1877171e9590..6fa86e8bfb89 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5776,6 +5776,68 @@  int perf_event_period(struct perf_event *event, u64 value)
 }
 EXPORT_SYMBOL_GPL(perf_event_period);
 
+static void __perf_event_topdown_metrics(struct perf_event *event,
+					 struct perf_cpu_context *cpuctx,
+					 struct perf_event_context *ctx,
+					 void *info)
+{
+	struct td_metrics *td_metrics = (struct td_metrics *)info;
+	bool active;
+
+	active = (event->state == PERF_EVENT_STATE_ACTIVE);
+	if (active) {
+		perf_pmu_disable(event->pmu);
+		/*
+		 * We could be throttled; unthrottle now to avoid the tick
+		 * trying to unthrottle while we already re-started the event.
+		 */
+		if (event->hw.interrupts == MAX_INTERRUPTS) {
+			event->hw.interrupts = 0;
+			perf_log_throttle(event, 1);
+		}
+		event->pmu->stop(event, PERF_EF_UPDATE);
+	}
+
+	event->hw.saved_slots = td_metrics->slots;
+	event->hw.saved_metric = td_metrics->metric;
+
+	if (active) {
+		event->pmu->start(event, PERF_EF_RELOAD);
+		perf_pmu_enable(event->pmu);
+	}
+}
+
+static int _perf_event_topdown_metrics(struct perf_event *event,
+				       struct td_metrics *value)
+{
+	/*
+	 * Slots event in topdown metrics scenario
+	 * must be non-sampling event.
+	 */
+	if (is_sampling_event(event))
+		return -EINVAL;
+
+	if (!value)
+		return -EINVAL;
+
+	event_function_call(event, __perf_event_topdown_metrics, value);
+
+	return 0;
+}
+
+int perf_event_topdown_metrics(struct perf_event *event, struct td_metrics *value)
+{
+	struct perf_event_context *ctx;
+	int ret;
+
+	ctx = perf_event_ctx_lock(event);
+	ret = _perf_event_topdown_metrics(event, value);
+	perf_event_ctx_unlock(event, ctx);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(perf_event_topdown_metrics);
+
 static const struct file_operations perf_fops;
 
 static inline int perf_fget_light(int fd, struct fd *p)