diff mbox series

[V12,07/10] arm64/perf: Add PERF_ATTACH_TASK_DATA to events with has_branch_stack()

Message ID 20230615133239.442736-8-anshuman.khandual@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64/perf: Enable branch stack sampling | expand

Commit Message

Anshuman Khandual June 15, 2023, 1:32 p.m. UTC 
Short running processes i.e those getting very small cpu run time each time
when they get scheduled on, might not accumulate much branch records before
a PMU IRQ really happens. This increases possibility, for such processes to
loose much of its branch records, while being scheduled in-out of various
cpus on the system.

There is a need to save all occurred branch records during the cpu run time
while the process gets scheduled out. It requires an event context specific
buffer for such storage.

This adds PERF_ATTACH_TASK_DATA flag unconditionally, for all branch stack
sampling events, which would allocate task_ctx_data during its event init.
This also creates a platform specific task_ctx_data kmem cache which will
serve such allocation requests.

This adds a new structure 'arm64_perf_task_context' which encapsulates brbe
register set for maximum possible BRBE entries on the HW along with a valid
records tracking element.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Tested-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/include/asm/perf_event.h |  4 ++++
 drivers/perf/arm_brbe.c             | 21 +++++++++++++++++++++
 drivers/perf/arm_brbe.h             | 13 +++++++++++++
 drivers/perf/arm_pmuv3.c            | 16 +++++++++++++---
 4 files changed, 51 insertions(+), 3 deletions(-)

Comments

kernel test robot June 16, 2023, 2:38 a.m. UTC | #1 
Hi Anshuman,

kernel test robot noticed the following build errors:

[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on tip/perf/core acme/perf/core linus/master v6.4-rc6 next-20230615]
[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/20230615-223352
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
patch link:    https://lore.kernel.org/r/20230615133239.442736-8-anshuman.khandual%40arm.com
patch subject: [PATCH V12 07/10] arm64/perf: Add PERF_ATTACH_TASK_DATA to events with has_branch_stack()
config: arm-randconfig-r004-20230615 (https://download.01.org/0day-ci/archive/20230616/202306161016.jJeqG6mc-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        git remote add arm64 https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
        git fetch arm64 for-next/core
        git checkout arm64/for-next/core
        b4 shazam https://lore.kernel.org/r/20230615133239.442736-8-anshuman.khandual@arm.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/perf/

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/202306161016.jJeqG6mc-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/perf/arm_pmuv3.c:148:45: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
     148 |         [C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR,
         |                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmuv3.h:134:44: note: expanded from macro 'ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR'
     134 | #define ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR                         0x004F
         |                                                                 ^~~~~~
   drivers/perf/arm_pmuv3.c:140:2: note: previous initialization is here
     140 |         PERF_CACHE_MAP_ALL_UNSUPPORTED,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:43:31: note: expanded from macro 'PERF_CACHE_MAP_ALL_UNSUPPORTED'
      43 |                 [0 ... C(RESULT_MAX) - 1] = CACHE_OP_UNSUPPORTED,       \
         |                                             ^~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:35:31: note: expanded from macro 'CACHE_OP_UNSUPPORTED'
      35 | #define CACHE_OP_UNSUPPORTED            0xFFFF
         |                                         ^~~~~~
   drivers/perf/arm_pmuv3.c:149:42: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
     149 |         [C(DTLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
         |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmuv3.h:131:50: note: expanded from macro 'ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD'
     131 | #define ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD                  0x004C
         |                                                                 ^~~~~~
   drivers/perf/arm_pmuv3.c:140:2: note: previous initialization is here
     140 |         PERF_CACHE_MAP_ALL_UNSUPPORTED,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:43:31: note: expanded from macro 'PERF_CACHE_MAP_ALL_UNSUPPORTED'
      43 |                 [0 ... C(RESULT_MAX) - 1] = CACHE_OP_UNSUPPORTED,       \
         |                                             ^~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:35:31: note: expanded from macro 'CACHE_OP_UNSUPPORTED'
      35 | #define CACHE_OP_UNSUPPORTED            0xFFFF
         |                                         ^~~~~~
   drivers/perf/arm_pmuv3.c:150:43: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
     150 |         [C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]  = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
         |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmuv3.h:132:50: note: expanded from macro 'ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR'
     132 | #define ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR                  0x004D
         |                                                                 ^~~~~~
   drivers/perf/arm_pmuv3.c:140:2: note: previous initialization is here
     140 |         PERF_CACHE_MAP_ALL_UNSUPPORTED,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:43:31: note: expanded from macro 'PERF_CACHE_MAP_ALL_UNSUPPORTED'
      43 |                 [0 ... C(RESULT_MAX) - 1] = CACHE_OP_UNSUPPORTED,       \
         |                                             ^~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:35:31: note: expanded from macro 'CACHE_OP_UNSUPPORTED'
      35 | #define CACHE_OP_UNSUPPORTED            0xFFFF
         |                                         ^~~~~~
   drivers/perf/arm_pmuv3.c:152:44: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
     152 |         [C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
         |                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmuv3.h:148:46: note: expanded from macro 'ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD'
     148 | #define ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD                      0x0060
         |                                                                 ^~~~~~
   drivers/perf/arm_pmuv3.c:140:2: note: previous initialization is here
     140 |         PERF_CACHE_MAP_ALL_UNSUPPORTED,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:43:31: note: expanded from macro 'PERF_CACHE_MAP_ALL_UNSUPPORTED'
      43 |                 [0 ... C(RESULT_MAX) - 1] = CACHE_OP_UNSUPPORTED,       \
         |                                             ^~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:35:31: note: expanded from macro 'CACHE_OP_UNSUPPORTED'
      35 | #define CACHE_OP_UNSUPPORTED            0xFFFF
         |                                         ^~~~~~
   drivers/perf/arm_pmuv3.c:153:45: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides]
     153 |         [C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
         |                                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmuv3.h:149:46: note: expanded from macro 'ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR'
     149 | #define ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR                      0x0061
         |                                                                 ^~~~~~
   drivers/perf/arm_pmuv3.c:140:2: note: previous initialization is here
     140 |         PERF_CACHE_MAP_ALL_UNSUPPORTED,
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:43:31: note: expanded from macro 'PERF_CACHE_MAP_ALL_UNSUPPORTED'
      43 |                 [0 ... C(RESULT_MAX) - 1] = CACHE_OP_UNSUPPORTED,       \
         |                                             ^~~~~~~~~~~~~~~~~~~~
   include/linux/perf/arm_pmu.h:35:31: note: expanded from macro 'CACHE_OP_UNSUPPORTED'
      35 | #define CACHE_OP_UNSUPPORTED            0xFFFF
         |                                         ^~~~~~
   drivers/perf/arm_pmuv3.c:714:3: error: call to undeclared function 'armv8pmu_branch_enable'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     714 |                 armv8pmu_branch_enable(event);
         |                 ^
   drivers/perf/arm_pmuv3.c:720:3: error: call to undeclared function 'armv8pmu_branch_disable'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     720 |                 armv8pmu_branch_disable(event);
         |                 ^
   drivers/perf/arm_pmuv3.c:805:4: error: call to undeclared function 'armv8pmu_branch_read'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     805 |                         armv8pmu_branch_read(cpuc, event);
         |                         ^
   drivers/perf/arm_pmuv3.c:805:4: note: did you mean 'armv8pmu_pmcr_read'?
   drivers/perf/arm_pmuv3.c:430:19: note: 'armv8pmu_pmcr_read' declared here
     430 | static inline u32 armv8pmu_pmcr_read(void)
         |                   ^
   drivers/perf/arm_pmuv3.c:912:3: error: call to undeclared function 'armv8pmu_branch_reset'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     912 |                 armv8pmu_branch_reset();
         |                 ^
   drivers/perf/arm_pmuv3.c:987:3: error: call to undeclared function 'armv8pmu_branch_reset'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     987 |                 armv8pmu_branch_reset();
         |                 ^
   drivers/perf/arm_pmuv3.c:1026:8: error: call to undeclared function 'armv8pmu_branch_attr_valid'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1026 |                 if (!armv8pmu_branch_attr_valid(event))
         |                      ^
   drivers/perf/arm_pmuv3.c:1148:2: error: call to undeclared function 'armv8pmu_branch_probe'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1148 |         armv8pmu_branch_probe(cpu_pmu);
         |         ^
>> drivers/perf/arm_pmuv3.c:1195:9: error: call to undeclared function 'armv8pmu_task_ctx_cache_alloc'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1195 |                 ret = armv8pmu_task_ctx_cache_alloc(cpu_pmu);
         |                       ^
>> drivers/perf/arm_pmuv3.c:1201:4: error: call to undeclared function 'armv8pmu_task_ctx_cache_free'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1201 |                         armv8pmu_task_ctx_cache_free(cpu_pmu);
         |                         ^
   55 warnings and 9 errors generated.


vim +/armv8pmu_task_ctx_cache_alloc +1195 drivers/perf/arm_pmuv3.c

  1176	
  1177	static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu)
  1178	{
  1179		struct armv8pmu_probe_info probe = {
  1180			.pmu = cpu_pmu,
  1181			.present = false,
  1182		};
  1183		int ret;
  1184	
  1185		ret = smp_call_function_any(&cpu_pmu->supported_cpus,
  1186					    __armv8pmu_probe_pmu,
  1187					    &probe, 1);
  1188		if (ret)
  1189			return ret;
  1190	
  1191		if (!probe.present)
  1192			return -ENODEV;
  1193	
  1194		if (cpu_pmu->has_branch_stack) {
> 1195			ret = armv8pmu_task_ctx_cache_alloc(cpu_pmu);
  1196			if (ret)
  1197				return ret;
  1198	
  1199			ret = branch_records_alloc(cpu_pmu);
  1200			if (ret) {
> 1201				armv8pmu_task_ctx_cache_free(cpu_pmu);
  1202				return ret;
  1203			}
  1204		}
  1205		return 0;
  1206	}
  1207
Anshuman Khandual June 19, 2023, 6:28 a.m. UTC | #2 
On 6/16/23 08:08, kernel test robot wrote:
> Hi Anshuman,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on arm64/for-next/core]
> [also build test ERROR on tip/perf/core acme/perf/core linus/master v6.4-rc6 next-20230615]
> [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/20230615-223352
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
> patch link:    https://lore.kernel.org/r/20230615133239.442736-8-anshuman.khandual%40arm.com
> patch subject: [PATCH V12 07/10] arm64/perf: Add PERF_ATTACH_TASK_DATA to events with has_branch_stack()
> config: arm-randconfig-r004-20230615 (https://download.01.org/0day-ci/archive/20230616/202306161016.jJeqG6mc-lkp@intel.com/config)
> compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
> reproduce (this is a W=1 build):
>         mkdir -p ~/bin
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install arm cross compiling tool for clang build
>         # apt-get install binutils-arm-linux-gnueabi
>         git remote add arm64 https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
>         git fetch arm64 for-next/core
>         git checkout arm64/for-next/core
>         b4 shazam https://lore.kernel.org/r/20230615133239.442736-8-anshuman.khandual@arm.com
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm olddefconfig
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang ~/bin/make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/perf/

This build failure too gets solved via the header code block movement as mentioned earlier.
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/perf_event.h b/arch/arm64/include/asm/perf_event.h
index 49a973571415..b0c12a5882df 100644
--- a/arch/arm64/include/asm/perf_event.h
+++ b/arch/arm64/include/asm/perf_event.h
@@ -38,6 +38,8 @@  void armv8pmu_branch_enable(struct perf_event *event);
 void armv8pmu_branch_disable(struct perf_event *event);
 void armv8pmu_branch_probe(struct arm_pmu *arm_pmu);
 void armv8pmu_branch_reset(void);
+int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu);
+void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu);
 #else
 static inline void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event)
 {
@@ -62,6 +64,8 @@  static inline void armv8pmu_branch_disable(struct perf_event *event)
 
 static inline void armv8pmu_branch_probe(struct arm_pmu *arm_pmu) { }
 static inline void armv8pmu_branch_reset(void) { }
+static inline int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu) { return 0; }
+static inline void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu) { }
 #endif
 #endif
 #endif
diff --git a/drivers/perf/arm_brbe.c b/drivers/perf/arm_brbe.c
index 90bc9131223d..4729cb49282b 100644
--- a/drivers/perf/arm_brbe.c
+++ b/drivers/perf/arm_brbe.c
@@ -109,6 +109,27 @@  bool armv8pmu_branch_attr_valid(struct perf_event *event)
 	return true;
 }
 
+static inline struct kmem_cache *
+arm64_create_brbe_task_ctx_kmem_cache(size_t size)
+{
+	return kmem_cache_create("arm64_brbe_task_ctx", size, 0, 0, NULL);
+}
+
+int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu)
+{
+	size_t size = sizeof(struct arm64_perf_task_context);
+
+	arm_pmu->pmu.task_ctx_cache = arm64_create_brbe_task_ctx_kmem_cache(size);
+	if (!arm_pmu->pmu.task_ctx_cache)
+		return -ENOMEM;
+	return 0;
+}
+
+void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu)
+{
+	kmem_cache_destroy(arm_pmu->pmu.task_ctx_cache);
+}
+
 static int brbe_attributes_probe(struct arm_pmu *armpmu, u32 brbe)
 {
 	u64 brbidr = read_sysreg_s(SYS_BRBIDR0_EL1);
diff --git a/drivers/perf/arm_brbe.h b/drivers/perf/arm_brbe.h
index a47480eec070..4a72c2ba7140 100644
--- a/drivers/perf/arm_brbe.h
+++ b/drivers/perf/arm_brbe.h
@@ -80,12 +80,25 @@ 
  *	---------------------------------	------
  */
 #define BRBE_BANK_MAX_ENTRIES 32
+#define BRBE_MAX_BANK 2
+#define BRBE_MAX_ENTRIES (BRBE_BANK_MAX_ENTRIES * BRBE_MAX_BANK)
 
 #define BRBE_BANK0_IDX_MIN 0
 #define BRBE_BANK0_IDX_MAX 31
 #define BRBE_BANK1_IDX_MIN 32
 #define BRBE_BANK1_IDX_MAX 63
 
+struct brbe_regset {
+	unsigned long brbsrc;
+	unsigned long brbtgt;
+	unsigned long brbinf;
+};
+
+struct arm64_perf_task_context {
+	struct brbe_regset store[BRBE_MAX_ENTRIES];
+	int nr_brbe_records;
+};
+
 struct brbe_hw_attr {
 	int	brbe_version;
 	int	brbe_cc;
diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index 02907371523a..3c079051a63a 100644
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -1022,8 +1022,12 @@  static int __armv8_pmuv3_map_event(struct perf_event *event,
 
 	hw_event_id = __armv8_pmuv3_map_event_id(armpmu, event);
 
-	if (has_branch_stack(event) && !armv8pmu_branch_attr_valid(event))
-		return -EOPNOTSUPP;
+	if (has_branch_stack(event)) {
+		if (!armv8pmu_branch_attr_valid(event))
+			return -EOPNOTSUPP;
+
+		event->attach_state |= PERF_ATTACH_TASK_DATA;
+	}
 
 	/*
 	 * CHAIN events only work when paired with an adjacent counter, and it
@@ -1188,9 +1192,15 @@  static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu)
 		return -ENODEV;
 
 	if (cpu_pmu->has_branch_stack) {
-		ret = branch_records_alloc(cpu_pmu);
+		ret = armv8pmu_task_ctx_cache_alloc(cpu_pmu);
 		if (ret)
 			return ret;
+
+		ret = branch_records_alloc(cpu_pmu);
+		if (ret) {
+			armv8pmu_task_ctx_cache_free(cpu_pmu);
+			return ret;
+		}
 	}
 	return 0;
 }