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

[Adrian Hunter]

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@xxxxxxxxxx>
>>> ---
>>>  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.

> 
>>>          Field list can be prepended with the type, trace, sw or hw,
>>>          to indicate to which event type the field list applies.
>>>          e.g., -F sw:comm,tid,time,ip,sym  and -F trace:time,cpu,trace
>>> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
>>> index 4817a37f16e2..12d886694f6c 100644
>>> --- a/tools/perf/builtin-script.c
>>> +++ b/tools/perf/builtin-script.c
>>> @@ -135,6 +135,7 @@ enum perf_output_field {
>>>  	PERF_OUTPUT_CGROUP          = 1ULL << 39,
>>>  	PERF_OUTPUT_RETIRE_LAT      = 1ULL << 40,
>>>  	PERF_OUTPUT_DSOFF           = 1ULL << 41,
>>> +	PERF_OUTPUT_DISASM          = 1ULL << 42,
>>>  };
>>>  
>>>  struct perf_script {
>>> @@ -190,6 +191,7 @@ struct output_option {
>>>  	{.str = "bpf-output",   .field = PERF_OUTPUT_BPF_OUTPUT},
>>>  	{.str = "callindent", .field = PERF_OUTPUT_CALLINDENT},
>>>  	{.str = "insn", .field = PERF_OUTPUT_INSN},
>>> +	{.str = "disasm", .field = PERF_OUTPUT_DISASM},
>>>  	{.str = "insnlen", .field = PERF_OUTPUT_INSNLEN},
>>>  	{.str = "brstackinsn", .field = PERF_OUTPUT_BRSTACKINSN},
>>>  	{.str = "brstackoff", .field = PERF_OUTPUT_BRSTACKOFF},
>>> @@ -1515,6 +1517,10 @@ static int perf_sample__fprintf_insn(struct perf_sample *sample,
>>>  		printed += fprintf(fp, " insn: ");
>>>  		printed += sample__fprintf_insn_raw(sample, fp);
>>>  	}
>>> +	if (PRINT_FIELD(DISASM) && sample->insn_len) {
>>> +		printed += fprintf(fp, " insn: ");
>>> +		printed += sample__fprintf_insn(sample, thread, machine, fp);
>>> +	}
>>>  	if (PRINT_FIELD(BRSTACKINSN) || PRINT_FIELD(BRSTACKINSNLEN))
>>>  		printed += perf_sample__fprintf_brstackinsn(sample, thread, attr, machine, fp);
>>>  
>>> @@ -3900,7 +3906,7 @@ int cmd_script(int argc, const char **argv)
>>>  		     "Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,dsoff,"
>>>  		     "addr,symoff,srcline,period,iregs,uregs,brstack,"
>>>  		     "brstacksym,flags,data_src,weight,bpf-output,brstackinsn,"
>>> -		     "brstackinsnlen,brstackoff,callindent,insn,insnlen,synth,"
>>> +		     "brstackinsnlen,brstackoff,callindent,insn,disasm,insnlen,synth,"
>>>  		     "phys_addr,metric,misc,srccode,ipc,tod,data_page_size,"
>>>  		     "code_page_size,ins_lat,machine_pid,vcpu,cgroup,retire_lat",
>>>  		     parse_output_fields),
>>
>