[v1,0/4] perf arm-spe: Allow synthesizing of branch

Message

Graham Woodward Oct. 25, 2024, 2:30 p.m. UTC

Currently the --itrace=b will only show branch-misses but this change
allows perf to synthesize branches as well.

The change also incorporates the ability to display the target
addresses when specifying the addr field if the instruction is a branch.

Graham Woodward (4):
  perf arm-spe: Set sample.addr to target address for instruction sample
  perf arm-spe: Use ARM_SPE_OP_BRANCH_ERET when synthesizing branches
  perf arm-spe: Correctly set sample flags
  perf arm-spe: Update --itrace help text

 tools/perf/Documentation/itrace.txt       |  2 +-
 tools/perf/Documentation/perf-arm-spe.txt |  2 +-
 tools/perf/builtin-script.c               |  1 +
 tools/perf/util/arm-spe.c                 | 31 ++++++++++++++++++-----
 tools/perf/util/auxtrace.h                |  3 +--
 tools/perf/util/event.h                   |  1 +
 6 files changed, 29 insertions(+), 11 deletions(-)

Comments

Leo Yan Oct. 25, 2024, 5:33 p.m. UTC | #1

On Fri, Oct 25, 2024 at 03:30:05PM +0100, Graham Woodward wrote:
> 
> Currently the --itrace=b will only show branch-misses but this change
> allows perf to synthesize branches as well.
> 
> The change also incorporates the ability to display the target
> addresses when specifying the addr field if the instruction is a branch.

Tested for this series:

  # perf record -e arm_spe_0/branch_filter=1,load_filter=1/u \
      -- ./false_sharing.exe 1

  # perf script --itrace=i10ib  -F,+addr,+flags
    false_sharing.e  880532 [005] 1852579.389533:          1                                    branch:   jmp                       ffff91beb224     ffff91beb220 __GI___tunables_init+0x40 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389538:          1                                    branch:   jmp                       ffff91bec318     ffff91bec314 _dl_next_ld_env_entry+0x24 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389620:          1                                    branch:   jmp                       ffff91be0f14     ffff91be0f10 _dl_new_object+0x168 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389802:          1                                    branch:   jmp                       ffff91be2cf0     ffff91be2cec _dl_map_object_deps+0x3f4 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389802:         10                              instructions:   jmp                       ffff91be2cf0     ffff91be2cec _dl_map_object_deps+0x3f4 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389824:          1                                    branch:   br miss                   ffff91bee4e4     ffff91bee4e0 strcmp+0xa0 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389849:          1                                    branch:   jmp                       ffff91be1868     ffff91be1880 _dl_relocate_object+0x4a8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389858:          1                                    branch:   jmp                       ffff91be1868     ffff91be1880 _dl_relocate_object+0x4a8 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389861:          1                                    branch:   jmp                       ffff91be1c20     ffff91be1bcc _dl_relocate_object+0x7f4 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389875:         10                              instructions:                                        0     ffff91bdfe38 _dl_lookup_symbol_x+0x58 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389876:          1                                    branch:   jmp                       ffff91bdf3a8     ffff91bdf434 do_lookup_x+0x114 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389879:          1                                    branch:   jmp                       ffff91be18ec     ffff91be18e8 _dl_relocate_object+0x510 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389886:          1                                    branch:   jmp                       ffff91bee440     ffff91bdf2dc check_match+0x154 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389890:          1                                    branch:   jmp                       ffff91bdfed4     ffff91bdfed0 _dl_lookup_symbol_x+0xf0 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389893:         10                              instructions:                                        0     ffff91be1974 _dl_relocate_object+0x59c (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389894:          1                                    branch:   jmp                       ffff91bdf3f4     ffff91bdf3f0 do_lookup_x+0xd0 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)
    false_sharing.e  880532 [005] 1852579.389906:          1                                    branch:   jmp                       ffff91bdfea4     ffff91bdfe90 _dl_lookup_symbol_x+0xb0 (/usr/lib/aarch64-linux-gnu/ld-2.31.so)

  # perf test "Check Arm SPE"
  114: Check Arm SPE trace data recording and synthesized samples      : Ok
  115: Check Arm SPE doesn't hang when there are forks                 : Ok

Tested-by: Leo Yan <[e-mail]>