[Bug binutils/29081] New: objdump -S tends to be slow for thunderbird with separate debug info

[mliska at suse dot cz]

https://sourceware.org/bugzilla/show_bug.cgi?id=29081

            Bug ID: 29081
           Summary: objdump -S tends to be slow for thunderbird with
                    separate debug info
           Product: binutils
           Version: 2.37
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: binutils
          Assignee: unassigned at sourceware dot org
          Reporter: mliska at suse dot cz
  Target Milestone: ---

The debug info are big, so it's easiest to use a Docker image one can run
locally:

$ cat Dockerfile-thunderbird-objdump
FROM opensuse/tumbleweed
RUN zypper ar -f -c http://download.opensuse.org/source/tumbleweed/repo/oss/
source
RUN zypper ar -f -c http://download.opensuse.org/debug/tumbleweed/repo/oss/
debug
RUN zypper repos
RUN zypper refresh
RUN zypper -n install binutils MozillaThunderbird
MozillaThunderbird-debugsource MozillaThunderbird-debuginfo perf
RUN timeout 30 objdump --start-address=0x00000000017529e0
--stop-address=0x0000000001752c90 -S -d /usr/lib64/thunderbird/libxul.so

$ podman build -t test -f Dockerfile-thunderbird-objdump
STEP 1/7: FROM opensuse/tumbleweed
STEP 2/7: RUN zypper ar -f -c
http://download.opensuse.org/source/tumbleweed/repo/oss/ source
--> Using cache
2393dd1a2d437960601510c9b9732d59c6a2b10e497e4f497c85bda870b88dc5
--> 2393dd1a2d4
STEP 3/7: RUN zypper ar -f -c
http://download.opensuse.org/debug/tumbleweed/repo/oss/ debug
--> Using cache
40f7646c586e72ca9247283da6c8cdc9388f18b636d879d3300afabc5c22d229
--> 40f7646c586
STEP 4/7: RUN zypper repos
--> Using cache
8df3cd9239213c4d6857eb8c006ee239d45c0901571675c2701b0e68be74046b
--> 8df3cd92392
STEP 5/7: RUN zypper refresh
--> Using cache
aeaaa59b2269d0af55364f3fabda58d9ae055fdc19ffe56aa7d3e0160723f552
--> aeaaa59b226
STEP 6/7: RUN zypper -n install binutils MozillaThunderbird
MozillaThunderbird-debugsource MozillaThunderbird-debuginfo perf
--> Using cache
a4759602ecae1b53fe809c2835d42f607740a54bb42e491ea8cd8a3bc7ba6ae3
--> a4759602eca
STEP 7/7: RUN timeout 30 objdump --start-address=0x00000000017529e0
--stop-address=0x0000000001752c90 -S -d /usr/lib64/thunderbird/libxul.so

/usr/lib64/thunderbird/libxul.so:     file format elf64-x86-64


Disassembly of section .text:

00000000017529e0
<_ZN7mozilla3gfx11VsyncSource7Display11NotifyVsyncERKNS_9TimeStampES5_>:
objdump: DWARF error: could not find variable specification at offset 0x14bfaa4
objdump: DWARF error: could not find variable specification at offset 0x79e96
objdump: DWARF error: could not find variable specification at offset 0x14fb52b
objdump: DWARF error: could not find variable specification at offset 0x14fb536
objdump: DWARF error: could not find variable specification at offset 0x14fb866
objdump: DWARF error: could not find variable specification at offset 0x1570854
objdump: DWARF error: could not find variable specification at offset 0x15a62fb
objdump: DWARF error: could not find variable specification at offset 0x15a6a5f
objdump: DWARF error: could not find variable specification at offset 0x15a7fde
objdump: DWARF error: could not find variable specification at offset 0x15a927f
objdump: DWARF error: could not find variable specification at offset 0x15ad94a
objdump: DWARF error: could not find variable specification at offset 0x15a89fe
objdump: DWARF error: could not find variable specification at offset 0x15ad9bc
objdump: DWARF error: could not find variable specification at offset 0x15a6b27
objdump: DWARF error: could not find variable specification at offset 0x15ada15
objdump: DWARF error: could not find variable specification at offset 0x15a69f7
objdump: DWARF error: could not find variable specification at offset 0x15a8dd9
objdump: DWARF error: could not find variable specification at offset 0x15a809b
objdump: DWARF error: could not find variable specification at offset 0x15adc31
objdump: DWARF error: could not find variable specification at offset 0x15adcc3
objdump: DWARF error: could not find variable specification at offset 0x15a89dc
objdump: DWARF error: could not find variable specification at offset 0x15add48
objdump: DWARF error: could not find variable specification at offset 0x15add88
objdump: DWARF error: could not find variable specification at offset 0x15a6298
objdump: DWARF error: could not find variable specification at offset 0x15adacf
objdump: DWARF error: could not find variable specification at offset 0x15add03
objdump: DWARF error: could not find variable specification at offset 0x15adc7e
objdump: DWARF error: could not find variable specification at offset 0x15addd2
objdump: DWARF error: could not find variable specification at offset 0x83147e
objdump: DWARF error: could not find variable specification at offset 0x15c988e
objdump: DWARF error: could not find variable specification at offset 0x831489
objdump: DWARF error: could not find variable specification at offset 0x15c9899
objdump: DWARF error: could not find variable specification at offset 0x831494
objdump: DWARF error: could not find variable specification at offset 0x15c98a4
objdump: DWARF error: could not find variable specification at offset 0x83149f
objdump: DWARF error: could not find variable specification at offset 0x15c9fc5
objdump: DWARF error: could not find variable specification at offset 0x15ca89d
objdump: DWARF error: could not find variable specification at offset 0x15cafef
objdump: DWARF error: could not find variable specification at offset 0xc4842
objdump: DWARF error: could not find variable specification at offset 0xf2d9bf
objdump: DWARF error: could not find variable specification at offset 0x117a6f6
Error: error building at STEP "RUN timeout 30 objdump
--start-address=0x00000000017529e0 --stop-address=0x0000000001752c90 -S -d
/usr/lib64/thunderbird/libxul.so": error while running runtime: exit status 124

Note it's LTO-ed binary built with GCC.

perf shows the time is spent here:

$ perf report --stdio | head -n20
# To display the perf.data header info, please use --header/--header-only
options.
#
#
# Total Lost Samples: 0
#
# Samples: 117K of event 'cycles:u'
# Event count (approx.): 125022478481
#
# Overhead  Command  Shared Object              Symbol                          
# ........  .......  ......................... 
...............................................
#
    76.03%  objdump  libbfd-2.38.20220411-4.so  [.]
comp_unit_maybe_decode_line_info.lto_priv.0
    11.80%  objdump  objdump                    [.] check_gnu_debuglink
     5.19%  objdump  libbfd-2.38.20220411-4.so  [.]
find_abstract_instance.lto_priv.0
     1.48%  objdump  libbfd-2.38.20220411-4.so  [.]
read_attribute_value.lto_priv.0
     0.85%  objdump  libbfd-2.38.20220411-4.so  [.] arange_add.lto_priv.0
     0.65%  objdump  objdump                    [.] compare_symbols
     0.43%  objdump  libbfd-2.38.20220411-4.so  [.]
_bfd_safe_read_leb128.constprop.0
     0.37%  objdump  libc.so.6                  [.] __strlen_avx2
     0.30%  objdump  libc.so.6                  [.] __GI_strstr

and note w/o -S option it finishes pretty quickly:

$ time objdump --start-address=0x00000000017529e0
--stop-address=0x0000000001752c90 -d /usr/lib64/thunderbird/libxul.so
...
 1752c77:       5b                      pop    %rbx
 1752c78:       5d                      pop    %rbp
 1752c79:       41 5c                   pop    %r12
 1752c7b:       41 5d                   pop    %r13
 1752c7d:       41 5e                   pop    %r14
 1752c7f:       41 5f                   pop    %r15
 1752c81:       e9 ca c3 22 ff          jmp    97f050
<_ZN7mozilla6detail9MutexImpl6unlockEv@plt>
 1752c86:       e8 b5 a1 22 ff          call   97ce40 <__stack_chk_fail@plt>
 1752c8b:       0f 1f 44 00 00          nopl   0x0(%rax,%rax,1)

real    0m4.330s
user    0m3.998s
sys     0m0.332s

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