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Message-ID: <20240205121938.sl4ykpk25lgxhgfj@M910t>
Date: Mon, 5 Feb 2024 20:19:38 +0800
From: Changbin Du <changbin.du@...wei.com>
To: Adrian Hunter <adrian.hunter@...el.com>
CC: Changbin Du <changbin.du@...wei.com>, Peter Zijlstra
<peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>, Arnaldo Carvalho de
Melo <acme@...nel.org>, Mark Rutland <mark.rutland@....com>, Alexander
Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>,
Namhyung Kim <namhyung@...nel.org>, Ian Rogers <irogers@...gle.com>,
<linux-kernel@...r.kernel.org>, <linux-perf-users@...r.kernel.org>, Andi
Kleen <ak@...ux.intel.com>, Thomas Richter <tmricht@...ux.ibm.com>,
<changbin.du@...il.com>
Subject: Re: [PATCH v5 3/5] perf: script: add field 'disasm' to display
mnemonic instructions
On Mon, Feb 05, 2024 at 11:23:21AM +0200, Adrian Hunter wrote:
> On 22/01/24 13:20, 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) movq %rsp, %rdi
> > ls 1443864 [006] 2275506.209908: 1 branches:uH: 7f216b426103 _start+0x3 (/usr/lib/x86_64-linux-gnu/ld-2.31.so) callq _dl_start+0x0
> >
> > Signed-off-by: Changbin Du <changbin.du@...wei.com>
> >
> > ---
> > v2:
> > - update Documentation.
> > ---
> > tools/perf/Documentation/perf-script.txt | 13 +++++++------
> > tools/perf/builtin-script.c | 8 +++++++-
> > 2 files changed, 14 insertions(+), 7 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
> > index ff9a52e44688..578fa59f51a5 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.
> > +
> > 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
> > @@ -217,9 +218,9 @@ OPTIONS
> > Instruction Trace decoding. For calls and returns, it will display the
> > name of the symbol indented with spaces to reflect the stack depth.
> >
> > - When doing instruction trace decoding insn and insnlen give the
> > - instruction bytes and the instruction length of the current
> > - instruction.
> > + 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.
> >
> > The synth field is used by synthesized events which may be created when
> > Instruction Trace decoding.
> > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> > index 4817a37f16e2..4ac9670704ff 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, "\t\t");
>
> This is good, except if both 'insn' and 'disasm' are used together.
> It either:
> a) without libcapstone, prints insn bytes twice
>
> Probably simpler to make 'disasm' without libcapstone
> a fatal error explaining that perf needs to be built
> with libcapstone support for 'disasm' to work.
>
Instead of fatal error, I print a warning message for this. Because
perf_sample__fprintf_insn() cannot return negtive error number.
> b) with libcapstone, disassembly does not line up nicely
>
--
Cheers,
Changbin Du
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