Hello, On Mon, May 6, 2024 at 5:19 AM Athira Rajeev <atraj...@linux.vnet.ibm.com> wrote: > > 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, this patchset adds support to use > raw instruction. With raw instruction, macros are added to extract opcode > and register fields. > > 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 > > 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 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, 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 is to fix a small comment > - Patch 4 adds support to capture and parse raw instruction in objdump > by keeping existing approach intact. > - Patch 5 update parameters for reg extract functions to use raw > instruction on powerpc > - Patch 6 and patch 7 handles instruction tracking for powerpc. > - Patch 8 and Patch 8 handles support to find global register variables > > 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 562, ok 441 (78.5%), bad 121 (21.5%) > > Name : Good Bad > ----------------------------------------------------------- > ld : 313 54 > lwz : 51 32 > lbz : 31 5 > ldx : 6 21 > lhz : 23 0 > lwa : 4 3 > lwarx : 5 0 > lwzx : 2 2 > ldarx : 3 0 > lwzu : 2 0 > stdcx. : 0 1 > nop : 0 1 > ldu : 1 0 > lbzx : 0 1 > lwax : 0 1 > > perf report logs: > > # Samples: 1K of event 'mem-loads' > # Event count (approx.): 937238 > # > # Overhead Data Type Data Type Offset > # ........ ......... ................ > # > 48.81% (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) > 2.68% struct paca_struct struct paca_struct +8 (paca_index) > 2.64% struct paca_struct struct paca_struct +2808 (canary) > 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) > 1.00% struct menu_device struct menu_device +4 (tick_wakeup) > 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)
Looks great! I'm glad it worked on powerpc too. We still need to verify the returned type is properly annotated. But overall it looks really good, I will leave comments in reply. Thanks, Namhyung > > Thanks > Athira Rajeev > > Changelog: > 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 (9): > 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: Fix a comment about multi_regs in extract_reg_offset > function > tools/perf: Add support to capture and parse raw instruction in > objdump > tools/perf: Update parameters for reg extract functions to use raw > instruction on powerpc > tools/perf: Update instruction tracking for powerpc > tools/perf: Update instruction tracking with add instruction > 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/include/linux/string.h | 2 + > tools/lib/string.c | 13 + > .../perf/arch/powerpc/annotate/instructions.c | 84 +++ > tools/perf/arch/powerpc/util/dwarf-regs.c | 52 ++ > tools/perf/arch/x86/annotate/instructions.c | 383 +++++++++++++ > tools/perf/util/annotate-data.c | 519 +++--------------- > tools/perf/util/annotate-data.h | 78 +++ > tools/perf/util/annotate.c | 32 +- > tools/perf/util/annotate.h | 1 + > tools/perf/util/disasm.c | 109 +++- > tools/perf/util/disasm.h | 17 +- > tools/perf/util/dwarf-aux.c | 1 + > tools/perf/util/dwarf-aux.h | 1 + > tools/perf/util/include/dwarf-regs.h | 12 + > tools/perf/util/sort.c | 7 +- > 15 files changed, 854 insertions(+), 457 deletions(-) > > -- > 2.43.0 >
