Re: [PATCH v4 3/5] perf: script: add field 'disasm' to display mnemonic instructions

[Changbin Du <changbin.du@huawei.com>]

On Mon, Jan 22, 2024 at 11:59:13AM +0200, Adrian Hunter wrote:
> On 20/01/24 09:40, Changbin Du wrote:
> > On Fri, Jan 19, 2024 at 08:39:36PM +0200, Adrian Hunter wrote:
> >> On 19/01/24 12:48, Changbin Du wrote:
> >>> In addition to the 'insn' field, this adds a new field 'disasm' to
> >>> display mnemonic instructions instead of the raw code.
> >>>
> >>> $ sudo perf script -F +disasm
> >>>        perf-exec 1443864 [006] 2275506.209848:          psb:  psb offs: 0                                      0 [unknown] ([unknown])
> >>>        perf-exec 1443864 [006] 2275506.209848:          cbr:  cbr: 41 freq: 4100 MHz (114%)                    0 [unknown] ([unknown])
> >>>               ls 1443864 [006] 2275506.209905:          1  branches:uH:      7f216b426100 _start+0x0 (/usr/lib/x86_64-linux-gnu/ld-2.31.so) insn: movq %rsp, %rdi
> >>>               ls 1443864 [006] 2275506.209908:          1  branches:uH:      7f216b426103 _start+0x3 (/usr/lib/x86_64-linux-gnu/ld-2.31.so) insn: callq _dl_start+0x0
> >>>
> >>> Signed-off-by: Changbin Du <changbin.du@huawei.com>
> >>> ---
> >>>  tools/perf/Documentation/perf-script.txt | 7 ++++---
> >>>  tools/perf/builtin-script.c              | 8 +++++++-
> >>>  2 files changed, 11 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
> >>> index ff9a52e44688..fc79167c6bf8 100644
> >>> --- a/tools/perf/Documentation/perf-script.txt
> >>> +++ b/tools/perf/Documentation/perf-script.txt
> >>> @@ -132,9 +132,10 @@ OPTIONS
> >>>          Comma separated list of fields to print. Options are:
> >>>          comm, tid, pid, time, cpu, event, trace, ip, sym, dso, dsoff, addr, symoff,
> >>>          srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output,
> >>> -        brstackinsn, brstackinsnlen, brstackoff, callindent, insn, insnlen, synth,
> >>> -        phys_addr, metric, misc, srccode, ipc, data_page_size, code_page_size, ins_lat,
> >>> -        machine_pid, vcpu, cgroup, retire_lat.
> >>> +        brstackinsn, brstackinsnlen, brstackoff, callindent, insn, disasm,
> >>> +        insnlen, synth, phys_addr, metric, misc, srccode, ipc, data_page_size,
> >>> +        code_page_size, ins_lat, machine_pid, vcpu, cgroup, retire_lat.
> >>> +
> >>
> >> Further down, there are explanations for insn and insnlen.  disasm
> >> could be added there.
> >>
> > Updated as:
> > 
> > 	When doing instruction trace decoding, insn, disasm and insnlen give the
> > 	instruction bytes, disassembled instructions and the instruction length
> > 	of the current instruction respectively.
> 
> I wondered about mentioning that disasm needs perf to be compiled with
> disassembler support, but with a permissive license it seems likely
> that libcapstone support would generally be built into perf, so that
> should be fine.
> 
Yes, libcapstone has a permissive license. It's available on most Linux distros.

So, I updated as below:

	When doing instruction trace decoding, insn, disasm and insnlen give the
	instruction bytes, disassembled instructions (requires libcapstone support)
	and the instruction length of the current instruction respectively.

-- 
Cheers,
Changbin Du