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

Leo Yan leo.yan at arm.com
Fri Oct 25 10:33:30 PDT 2024


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 <leo.yan at arm.com>



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