The patchset from Namhyung added support for data type profiling in perf tool. This enabled support to associate PMU samples to data types they refer using DWARF debug information. With the upstream perf, currently it possible to run perf report or perf annotate to view the data type information on x86.
Initial patchset posted here had changes need to enable data type profiling support for powerpc. https://lore.kernel.org/all/6e09dc28-4a2e-49d8-a2b5-ffb3396a9...@csgroup.eu/T/ Main change were: 1. powerpc instruction nmemonic table to associate load/store instructions with move_ops which is use to identify if instruction is a memory access one. 2. To get register number and access offset from the given instruction, code uses fields from "struct arch" -> objump. Added entry for powerpc here. 3. A get_arch_regnum to return register number from the register name string. But the apporach used in the initial patchset used parsing of disassembled code which the current perf tool implementation does. Example: lwz r10,0(r9) This line "lwz r10,0(r9)" is parsed to extract instruction name, registers names and offset. Also to find whether there is a memory reference in the operands, "memory_ref_char" field of objdump is used. For x86, "(" is used as memory_ref_char to tackle instructions of the form "mov (%rax), %rcx". In case of powerpc, not all instructions using "(" are the only memory instructions. Example, above instruction can also be of extended form (X form) "lwzx r10,0,r19". Inorder to easy identify the instruction category and extract the source/target registers, second patchset added support to use raw instruction. With raw instruction, macros are added to extract opcode and register fields. Link to second patchset: https://lore.kernel.org/all/20240506121906.76639-1-atraj...@linux.vnet.ibm.com/ Example representation using --show-raw-insn in objdump gives result: 38 01 81 e8 ld r4,312(r1) Here "38 01 81 e8" is the raw instruction representation. In powerpc, this translates to instruction form: "ld RT,DS(RA)" and binary code as: _____________________________________ | 58 | RT | RA | DS | | ------------------------------------- 0 6 11 16 30 31 Second patchset used "objdump" again to read the raw instruction. But since there is no need to disassemble and binary code can be read directly from the DSO, third patchset (ie this patchset) uses below apporach. The apporach preferred in powerpc to parse sample for data type profiling in V3 patchset is: - Read directly from DSO using dso__data_read_offset - If that fails for any case, fallback to using libcapstone - If libcapstone is not supported, approach will use objdump Patchset adds support to pick the opcode and reg fields from this raw/binary instruction code. This approach came in from review comment by Segher Boessenkool and Christophe for the initial patchset. Apart from that, instruction tracking is enabled for powerpc and support function is added to find variables defined as registers Example, in powerpc, below two registers are defined to represent variable: 1. r13: represents local_paca register struct paca_struct *local_paca asm("r13"); 2. r1: represents stack_pointer register void *__stack_pointer asm("r1"); These are handled in this patchset. - Patch 1 is to rearrange register state type structures to header file so that it can referred from other arch specific files - Patch 2 is to make instruction tracking as a callback to"struct arch" so that it can be implemented by other archs easily and defined in arch specific files - Patch 3 adds support to capture and parse raw instruction in powerpc using dso__data_read_offset utility - Patch 4 adds logic to support using objdump when doing default "perf report" or "perf annotate" since it that needs disassembled instruction. - Patch 5 adds disasm_line__parse to parse raw instruction for powerpc - Patch 6 update parameters for reg extract functions to use raw instruction on powerpc - Patch 7 add support to identify memory instructions of opcode 31 in powerpc - Patch 8 adds more instructions to support instruction tracking in powerpc - Patch 9 and 10 handles instruction tracking for powerpc. - Patch 11, 12 and 13 add support to use libcapstone in powerpc - Patch 14 and patch 15 handles support to find global register variables - Patch 16 handles insn-stat option for perf annotate Note: - There are remaining unknowns (25%) as seen in annotate Instruction stats below. - This patchset is not tested on powerpc32. In next step of enhancements along with handling remaining unknowns, plan to cover powerpc32 changes based on how testing goes. With the current patchset: ./perf record -a -e mem-loads sleep 1 ./perf report -s type,typeoff --hierarchy --group --stdio ./perf annotate --data-type --insn-stat perf annotate logs: ================== Annotate Instruction stats total 609, ok 446 (73.2%), bad 163 (26.8%) Name/opcode: Good Bad ----------------------------------------------------------- 58 : 323 80 32 : 49 43 34 : 33 11 OP_31_XOP_LDX : 8 20 40 : 23 0 OP_31_XOP_LWARX : 5 1 OP_31_XOP_LWZX : 2 3 OP_31_XOP_LDARX : 3 0 33 : 0 2 OP_31_XOP_LBZX : 0 1 OP_31_XOP_LWAX : 0 1 OP_31_XOP_LHZX : 0 1 perf report logs: ================= Total Lost Samples: 0 Samples: 1K of event 'mem-loads' Event count (approx.): 937238 Overhead Data Type Data Type Offset ........ ......... ................ 48.60% (unknown) (unknown) +0 (no field) 12.85% long unsigned int long unsigned int +0 (current_stack_pointer) 4.68% struct paca_struct struct paca_struct +2312 (__current) 4.57% struct paca_struct struct paca_struct +2354 (irq_soft_mask) 2.69% struct paca_struct struct paca_struct +2808 (canary) 2.68% struct paca_struct struct paca_struct +8 (paca_index) 2.24% struct paca_struct struct paca_struct +48 (data_offset) 1.41% struct vm_fault struct vm_fault +0 (vma) 1.29% struct task_struct struct task_struct +276 (flags) 1.03% struct pt_regs struct pt_regs +264 (user_regs.msr) 0.90% struct security_hook_list struct security_hook_list +0 (list.next) 0.76% struct irq_desc struct irq_desc +304 (irq_data.chip) 0.76% struct rq struct rq +2856 (cpu) Thanks Athira Rajeev Changelog: >From v3->v4: - Addressed review comments from Ian by using capston_init from "util/print_insn.c" instead of "open_capston_handle". - Addressed review comment from Namhyung by moving "opcode" field from "struct ins" to "struct disasm_line" >From v2->v3: - Addressed review comments from Christophe and Namhyung for V2 - Changed the apporach in powerpc to parse sample for data type profiling as: Read directly from DSO using dso__data_read_offset If that fails for any case, fallback to using libcapstone If libcapstone is not supported, approach will use objdump - Include instructions with opcode as 31 and correctly categorize them as memory or arithmetic instructions. - Include more instructions for instruction tracking in powerpc >From v1->v2: - Addressed suggestion from Christophe Leroy and Segher Boessenkool to use the binary code (raw insn) to fetch opcode, register and offset fields. - Added support for instruction tracking in powerpc - Find the register defined variables (r13 and r1 which points to local_paca and current_stack_pointer in powerpc) Athira Rajeev (16): tools/perf: Move the data structures related to register type to header file tools/perf: Add "update_insn_state" callback function to handle arch specific instruction tracking tools/perf: Add support to capture and parse raw instruction in powerpc using dso__data_read_offset utility tools/perf: Use sort keys to determine whether to pick objdump to disassemble tools/perf: Add disasm_line__parse to parse raw instruction for powerpc tools/perf: Update parameters for reg extract functions to use raw instruction on powerpc tools/perf: Add support to identify memory instructions of opcode 31 in powerpc tools/perf: Add some of the arithmetic instructions to support instruction tracking in powerpc tools/perf: Add more instructions for instruction tracking tools/perf: Update instruction tracking for powerpc tools/perf: Make capstone_init non-static so that it can be used during symbol disassemble tools/perf: Use capstone_init and remove open_capstone_handle from disasm.c tools/perf: Add support to use libcapstone in powerpc tools/perf: Add support to find global register variables using find_data_type_global_reg tools/perf: Add support for global_die to capture name of variable in case of register defined variable tools/perf: Set instruction name to be used with insn-stat when using raw instruction tools/include/linux/string.h | 2 + tools/lib/string.c | 13 + tools/perf/arch/arm64/annotate/instructions.c | 3 +- .../arch/loongarch/annotate/instructions.c | 6 +- .../perf/arch/powerpc/annotate/instructions.c | 260 +++++++++ tools/perf/arch/powerpc/util/dwarf-regs.c | 53 ++ tools/perf/arch/s390/annotate/instructions.c | 5 +- tools/perf/arch/x86/annotate/instructions.c | 383 +++++++++++++ tools/perf/builtin-annotate.c | 4 +- tools/perf/util/annotate-data.c | 519 +++--------------- tools/perf/util/annotate-data.h | 78 +++ tools/perf/util/annotate.c | 35 +- tools/perf/util/annotate.h | 6 +- tools/perf/util/disasm.c | 475 ++++++++++++++-- tools/perf/util/disasm.h | 13 +- tools/perf/util/dwarf-aux.c | 1 + tools/perf/util/dwarf-aux.h | 1 + tools/perf/util/include/dwarf-regs.h | 4 + tools/perf/util/print_insn.c | 15 +- tools/perf/util/print_insn.h | 5 + tools/perf/util/sort.c | 7 +- 21 files changed, 1386 insertions(+), 502 deletions(-) -- 2.43.0
