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From: Andrii Nakryiko <andriin@fb.com>
To: <dwarves@vger.kernel.org>
Cc: <bpf@vger.kernel.org>, Andrii Nakryiko <andriin@fb.com>
Subject: [PATCH dwarves 00/11] Switch BTF loading and encoding to libbpf APIs
Date: Tue, 29 Sep 2020 21:27:31 -0700
Message-ID: <20200930042742.2525310-1-andriin@fb.com> (raw)

This patch set switches pahole to use libbpf-provided BTF loading and encoding
APIs. This reduces pahole's own BTF encoding code, speeds up the process,
reduces amount of RAM needed for DWARF-to-BTF conversion. Also, pahole finally
gets support to generating BTF for cross-compiled ELF binaries with different
endianness (patch #11).

Additionally, patch #6 fixes previously missed problem with invalid array
index type generation.

Patches #7-10 are speeding up DWARF-to-BTF convertion/dedup pretty
significantly, saving overall about 9 seconds out of current 27 or so.

Patch #8 revamps how per-CPU BTF variables are emitted, eliminating repeated
and expensive looping over ELF symbols table.

Patch #10 admittedly has some hacky parts to satisfy CTF use case, but its
speed ups are greatest. So I'll understand if it gets dropped, but it would be
a pity.

More details could be found in respective patches.

Andrii Nakryiko (11):
  libbpf: update to latest libbpf version
  btf_encoder: detect BTF encoding errors and exit
  dwarves: expose and maintain active debug info loader operations
  btf_loader: use libbpf to load BTF
  btf_encoder: use libbpf APIs to encode BTF type info
  btf_encoder: fix emitting __ARRAY_SIZE_TYPE__ as index range type
  btf_encoder: discard CUs after BTF encoding
  btf_encoder: revamp how per-CPU variables are encoded
  dwarf_loader: increase the size of lookup hash map
  strings: use BTF's string APIs for strings management
  btf_encoder: support cross-compiled ELF binaries with different
    endianness

 btf_encoder.c  | 361 +++++++++++++++------------
 btf_loader.c   | 244 +++++++-----------
 ctf_encoder.c  |   2 +-
 dwarf_loader.c |   2 +-
 dwarves.c      |   8 +
 lib/bpf        |   2 +-
 libbtf.c       | 661 +++++++++++++++++++++----------------------------
 libbtf.h       |  41 ++-
 libctf.c       |  14 +-
 libctf.h       |   4 +-
 pahole.c       |   9 +-
 strings.c      |  91 +++----
 strings.h      |  32 +--
 13 files changed, 653 insertions(+), 818 deletions(-)

-- 
2.24.1


             reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-30  4:27 Andrii Nakryiko [this message]
2020-09-30  4:27 ` [PATCH dwarves 01/11] libbpf: update to latest libbpf version Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 02/11] btf_encoder: detect BTF encoding errors and exit Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 03/11] dwarves: expose and maintain active debug info loader operations Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 04/11] btf_loader: use libbpf to load BTF Andrii Nakryiko
2020-10-08 18:06   ` Arnaldo Carvalho de Melo
2020-10-08 19:32     ` Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 05/11] btf_encoder: use libbpf APIs to encode BTF type info Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 06/11] btf_encoder: fix emitting __ARRAY_SIZE_TYPE__ as index range type Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 07/11] btf_encoder: discard CUs after BTF encoding Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 08/11] btf_encoder: revamp how per-CPU variables are encoded Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 09/11] dwarf_loader: increase the size of lookup hash map Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 10/11] strings: use BTF's string APIs for strings management Andrii Nakryiko
2020-09-30  4:27 ` [PATCH dwarves 11/11] btf_encoder: support cross-compiled ELF binaries with different endianness Andrii Nakryiko
2020-10-05  3:48 [PATCH dwarves 00/11] Switch BTF loading and encoding to libbpf APIs Tony Ambardar
2020-10-05 19:30 ` Andrii Nakryiko

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