From: Andrii Nakryiko <andrii@kernel.org>
To: <dwarves@vger.kernel.org>
Cc: <bpf@vger.kernel.org>, <kernel-team@fb.com>, <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: [PATCH v2 dwarves 0/8] Switch BTF loading and encoding to libbpf APIs
Date: Thu, 8 Oct 2020 16:39:52 -0700 [thread overview]
Message-ID: <20201008234000.740660-1-andrii@kernel.org> (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 #8).
Additionally, patch #3 fixes previously missed problem with invalid array
index type generation.
Patches #4-7 are speeding up DWARF-to-BTF convertion/dedup pretty
significantly, saving overall about 9 seconds out of current 27 or so.
Patch #5 revamps how per-CPU BTF variables are emitted, eliminating repeated
and expensive looping over ELF symbols table. The critical detail that took
few hours of investigation is that when DW_AT_variable has
DW_AT_specification, variable address (to correlate with symbol's address) has
to be taken before specification is followed.
More details could be found in respective patches.
v1->v2:
- rebase on latest dwarves master and fix var->spec's address problem.
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Andrii Nakryiko (8):
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 | 370 +++++++++++++++------------
btf_loader.c | 244 +++++++-----------
ctf_encoder.c | 2 +-
dwarf_loader.c | 2 +-
libbtf.c | 661 +++++++++++++++++++++----------------------------
libbtf.h | 41 ++-
libctf.c | 14 +-
libctf.h | 4 +-
pahole.c | 2 +-
strings.c | 91 +++----
strings.h | 32 +--
11 files changed, 645 insertions(+), 818 deletions(-)
--
2.24.1
next reply other threads:[~2020-10-08 23:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 23:39 Andrii Nakryiko [this message]
2020-10-08 23:39 ` [PATCH v2 dwarves 1/8] btf_loader: use libbpf to load BTF Andrii Nakryiko
2020-10-09 14:53 ` Arnaldo Carvalho de Melo
2020-10-09 17:49 ` Andrii Nakryiko
2020-10-08 23:39 ` [PATCH v2 dwarves 2/8] btf_encoder: use libbpf APIs to encode BTF type info Andrii Nakryiko
2020-10-08 23:39 ` [PATCH v2 dwarves 3/8] btf_encoder: fix emitting __ARRAY_SIZE_TYPE__ as index range type Andrii Nakryiko
2020-10-08 23:39 ` [PATCH v2 dwarves 4/8] btf_encoder: discard CUs after BTF encoding Andrii Nakryiko
2020-10-09 15:47 ` Arnaldo Carvalho de Melo
2020-10-08 23:39 ` [PATCH v2 dwarves 5/8] btf_encoder: revamp how per-CPU variables are encoded Andrii Nakryiko
2020-10-09 15:53 ` Arnaldo Carvalho de Melo
2020-10-08 23:39 ` [PATCH v2 dwarves 6/8] dwarf_loader: increase the size of lookup hash map Andrii Nakryiko
2020-10-08 23:39 ` [PATCH v2 dwarves 7/8] strings: use BTF's string APIs for strings management Andrii Nakryiko
2020-10-08 23:40 ` [PATCH v2 dwarves 8/8] btf_encoder: support cross-compiled ELF binaries with different endianness Andrii Nakryiko
2020-10-09 16:22 ` [PATCH v2 dwarves 0/8] Switch BTF loading and encoding to libbpf APIs Arnaldo Carvalho de Melo
2020-10-09 17:59 ` Andrii Nakryiko
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