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[dwarves,v4,RESEND,00/10] pahole: faster reproducible BTF encoding

Message ID 20250109185950.653110-1-ihor.solodrai@pm.me (mailing list archive)
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Series pahole: faster reproducible BTF encoding | expand

Message

Ihor Solodrai Jan. 9, 2025, 6:59 p.m. UTC
Note: a resend due to https://lore.kernel.org/dwarves/Z4AWJBNsGJvBU7ZY@x1/

This is v4 of the series aiming to speed up parallel reproducible BTF
encoding. This version mostly addresses feedback from Jiri Olsa on v3.

A notable adition is a patch 10/10, which changes func_states in
btf_encoder from a list to an array.

Testing:

    vmlinux=/home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1 PATH=$(realpath build):$PATH ./tests/tests
      1: Validation of BTF encoding of functions; this may take some time: Ok
      2: Default BTF on a system without BTF: Ok
      3: Flexible arrays accounting: pahole: type 'nft_pipapo_elem' not found
    pahole: type 'tls_rec' not found
    pahole: type 'fuse_direntplus' not found
    pahole: type 'nft_rhash_elem' not found
    pahole: type 'nft_hash_elem' not found
    pahole: type 'nft_bitmap_elem' not found
    pahole: type 'ipt_standard' not found
    pahole: type 'nft_rule_dp_last' not found
    pahole: type 'ip6t_standard' not found
    pahole: type 'ipt_error' not found
    pahole: type 'ip6t_error' not found
    pahole: type 'nft_rbtree_elem' not found
    Ok
      4: Check that pfunct can print btf_decl_tags read from BTF: Ok
      5: Pretty printing of files using DWARF type information: Ok
      6: Parallel reproducible DWARF Loading/Serial BTF encoding: Ok

The warnings about not found types are also present at pahole/next, so
not related to this patchset.


Performance check. This patchset (always reproducible):

     Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs,reproducible_build --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):

              5,788.22 msec cpu-clock:u                      #    3.776 CPUs utilized               ( +-  0.17% )

               1.53288 +- 0.00334 seconds time elapsed  ( +-  0.22% )


pahole/next (d444eb6), parallel non-reproducible:

     Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):

             10,462.38 msec cpu-clock:u                      #    6.678 CPUs utilized               ( +-  0.15% )

               1.56670 +- 0.00548 seconds time elapsed  ( +-  0.35% )


pahole/next (d444eb6), parallel reproducible:

     Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs,reproducible_build --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):

              6,399.88 msec cpu-clock:u                      #    3.164 CPUs utilized               ( +-  0.22% )

               2.02269 +- 0.00359 seconds time elapsed  ( +-  0.18% )


v3: https://lore.kernel.org/dwarves/20241221012245.243845-1-ihor.solodrai@pm.me/
v2: https://lore.kernel.org/dwarves/20241213223641.564002-1-ihor.solodrai@pm.me/
v1: https://lore.kernel.org/dwarves/20241128012341.4081072-1-ihor.solodrai@pm.me/

Alan Maguire (2):
  btf_encoder: simplify function encoding
  btf_encoder: separate elf function, saved function representations

Ihor Solodrai (8):
  btf_encoder: free encoder->secinfo in btf_encoder__delete
  btf_encoder: introduce elf_functions struct type
  btf_encoder: introduce elf_functions_list
  btf_encoder: remove skip_encoding_inconsistent_proto
  dwarf_loader: introduce cu->id
  dwarf_loader: multithreading with a job/worker model
  btf_encoder: clean up global encoders list
  btf_encoder: switch func_states from a list to an array

 btf_encoder.c               | 662 +++++++++++++++++++-----------------
 btf_encoder.h               |   7 +-
 btf_loader.c                |   2 +-
 ctf_loader.c                |   2 +-
 dwarf_loader.c              | 335 ++++++++++++------
 dwarves.c                   |  44 ---
 dwarves.h                   |  20 +-
 pahole.c                    | 230 ++-----------
 pdwtags.c                   |   3 +-
 pfunct.c                    |   3 +-
 tests/reproducible_build.sh |   5 +-
 11 files changed, 623 insertions(+), 690 deletions(-)

Comments

Jiri Olsa Jan. 9, 2025, 10:03 p.m. UTC | #1
On Thu, Jan 09, 2025 at 06:59:54PM +0000, Ihor Solodrai wrote:
> Note: a resend due to https://lore.kernel.org/dwarves/Z4AWJBNsGJvBU7ZY@x1/
> 
> This is v4 of the series aiming to speed up parallel reproducible BTF
> encoding. This version mostly addresses feedback from Jiri Olsa on v3.
> 
> A notable adition is a patch 10/10, which changes func_states in
> btf_encoder from a list to an array.
> 
> Testing:
> 
>     vmlinux=/home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1 PATH=$(realpath build):$PATH ./tests/tests
>       1: Validation of BTF encoding of functions; this may take some time: Ok
>       2: Default BTF on a system without BTF: Ok
>       3: Flexible arrays accounting: pahole: type 'nft_pipapo_elem' not found
>     pahole: type 'tls_rec' not found
>     pahole: type 'fuse_direntplus' not found
>     pahole: type 'nft_rhash_elem' not found
>     pahole: type 'nft_hash_elem' not found
>     pahole: type 'nft_bitmap_elem' not found
>     pahole: type 'ipt_standard' not found
>     pahole: type 'nft_rule_dp_last' not found
>     pahole: type 'ip6t_standard' not found
>     pahole: type 'ipt_error' not found
>     pahole: type 'ip6t_error' not found
>     pahole: type 'nft_rbtree_elem' not found
>     Ok
>       4: Check that pfunct can print btf_decl_tags read from BTF: Ok
>       5: Pretty printing of files using DWARF type information: Ok
>       6: Parallel reproducible DWARF Loading/Serial BTF encoding: Ok
> 
> The warnings about not found types are also present at pahole/next, so
> not related to this patchset.
> 
> 
> Performance check. This patchset (always reproducible):
> 
>      Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs,reproducible_build --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):
> 
>               5,788.22 msec cpu-clock:u                      #    3.776 CPUs utilized               ( +-  0.17% )
> 
>                1.53288 +- 0.00334 seconds time elapsed  ( +-  0.22% )
> 
> 
> pahole/next (d444eb6), parallel non-reproducible:
> 
>      Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):
> 
>              10,462.38 msec cpu-clock:u                      #    6.678 CPUs utilized               ( +-  0.15% )
> 
>                1.56670 +- 0.00548 seconds time elapsed  ( +-  0.35% )
> 
> 
> pahole/next (d444eb6), parallel reproducible:
> 
>      Performance counter stats for '/home/theihor/dev/dwarves/build/pahole -J -j24 --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func,decl_tag_kfuncs,reproducible_build --btf_encode_detached=/dev/null --lang_exclude=rust /home/theihor/kernels/bpf-next/kbuild-output/.tmp_vmlinux1' (13 runs):
> 
>               6,399.88 msec cpu-clock:u                      #    3.164 CPUs utilized               ( +-  0.22% )
> 
>                2.02269 +- 0.00359 seconds time elapsed  ( +-  0.18% )
> 
> 
> v3: https://lore.kernel.org/dwarves/20241221012245.243845-1-ihor.solodrai@pm.me/
> v2: https://lore.kernel.org/dwarves/20241213223641.564002-1-ihor.solodrai@pm.me/
> v1: https://lore.kernel.org/dwarves/20241128012341.4081072-1-ihor.solodrai@pm.me/
> 
> Alan Maguire (2):
>   btf_encoder: simplify function encoding
>   btf_encoder: separate elf function, saved function representations
> 
> Ihor Solodrai (8):
>   btf_encoder: free encoder->secinfo in btf_encoder__delete
>   btf_encoder: introduce elf_functions struct type
>   btf_encoder: introduce elf_functions_list
>   btf_encoder: remove skip_encoding_inconsistent_proto
>   dwarf_loader: introduce cu->id
>   dwarf_loader: multithreading with a job/worker model
>   btf_encoder: clean up global encoders list
>   btf_encoder: switch func_states from a list to an array

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> 
>  btf_encoder.c               | 662 +++++++++++++++++++-----------------
>  btf_encoder.h               |   7 +-
>  btf_loader.c                |   2 +-
>  ctf_loader.c                |   2 +-
>  dwarf_loader.c              | 335 ++++++++++++------
>  dwarves.c                   |  44 ---
>  dwarves.h                   |  20 +-
>  pahole.c                    | 230 ++-----------
>  pdwtags.c                   |   3 +-
>  pfunct.c                    |   3 +-
>  tests/reproducible_build.sh |   5 +-
>  11 files changed, 623 insertions(+), 690 deletions(-)
> 
> -- 
> 2.47.1
> 
>