On Thu, Nov 13, 2025 at 11:02 PM Namhyung Kim <[email protected]> wrote: > > Handle the deferred callchains in the script output. > > $ perf script > ... > pwd 2312 121.163435: 249113 cpu/cycles/P: > ffffffff845b78d8 __build_id_parse.isra.0+0x218 ([kernel.kallsyms]) > ffffffff83bb5bf6 perf_event_mmap+0x2e6 ([kernel.kallsyms]) > ffffffff83c31959 mprotect_fixup+0x1e9 ([kernel.kallsyms]) > ffffffff83c31dc5 do_mprotect_pkey+0x2b5 ([kernel.kallsyms]) > ffffffff83c3206f __x64_sys_mprotect+0x1f ([kernel.kallsyms]) > ffffffff845e6692 do_syscall_64+0x62 ([kernel.kallsyms]) > ffffffff8360012f entry_SYSCALL_64_after_hwframe+0x76 > ([kernel.kallsyms]) > b00000006 [unknown] ([unknown])
Does this unknown value correspond to the cookie? Can the cookie and deferred data be added to the kernel stack trace output? > pwd 2312 121.163447: DEFERRED CALLCHAIN > 7f18fe337fa7 mprotect+0x7 > (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > 7f18fe330e0f _dl_sysdep_start+0x7f > (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) > 7f18fe331448 _dl_start_user+0x0 > (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) Can we display the cookie here so that the user callchain can be matched with the kernel part? Thanks, Ian > Signed-off-by: Namhyung Kim <[email protected]> > --- > tools/perf/builtin-script.c | 89 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 89 insertions(+) > > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c > index cf0040bbaba9cbc9..3b2896350bad2924 100644 > --- a/tools/perf/builtin-script.c > +++ b/tools/perf/builtin-script.c > @@ -2719,6 +2719,93 @@ static int process_sample_event(const struct perf_tool > *tool, > return ret; > } > > +static int process_deferred_sample_event(const struct perf_tool *tool, > + union perf_event *event, > + struct perf_sample *sample, > + struct evsel *evsel, > + struct machine *machine) > +{ > + struct perf_script *scr = container_of(tool, struct perf_script, > tool); > + struct perf_event_attr *attr = &evsel->core.attr; > + struct evsel_script *es = evsel->priv; > + unsigned int type = output_type(attr->type); > + struct addr_location al; > + FILE *fp = es->fp; > + int ret = 0; > + > + if (output[type].fields == 0) > + return 0; > + > + /* Set thread to NULL to indicate addr_al and al are not initialized > */ > + addr_location__init(&al); > + > + if (perf_time__ranges_skip_sample(scr->ptime_range, scr->range_num, > + sample->time)) { > + goto out_put; > + } > + > + if (debug_mode) { > + if (sample->time < last_timestamp) { > + pr_err("Samples misordered, previous: %" PRIu64 > + " this: %" PRIu64 "\n", last_timestamp, > + sample->time); > + nr_unordered++; > + } > + last_timestamp = sample->time; > + goto out_put; > + } > + > + if (filter_cpu(sample)) > + goto out_put; > + > + if (machine__resolve(machine, &al, sample) < 0) { > + pr_err("problem processing %d event, skipping it.\n", > + event->header.type); > + ret = -1; > + goto out_put; > + } > + > + if (al.filtered) > + goto out_put; > + > + if (!show_event(sample, evsel, al.thread, &al, NULL)) > + goto out_put; > + > + if (evswitch__discard(&scr->evswitch, evsel)) > + goto out_put; > + > + perf_sample__fprintf_start(scr, sample, al.thread, evsel, > + PERF_RECORD_CALLCHAIN_DEFERRED, fp); > + fprintf(fp, "DEFERRED CALLCHAIN"); > + > + if (PRINT_FIELD(IP)) { > + struct callchain_cursor *cursor = NULL; > + > + if (symbol_conf.use_callchain && sample->callchain) { > + cursor = get_tls_callchain_cursor(); > + if (thread__resolve_callchain(al.thread, cursor, > evsel, > + sample, NULL, NULL, > + scripting_max_stack)) { > + pr_info("cannot resolve deferred > callchains\n"); > + cursor = NULL; > + } > + } > + > + fputc(cursor ? '\n' : ' ', fp); > + sample__fprintf_sym(sample, &al, 0, > output[type].print_ip_opts, > + cursor, symbol_conf.bt_stop_list, fp); > + } > + > + fprintf(fp, "\n"); > + > + if (verbose > 0) > + fflush(fp); > + > +out_put: > + addr_location__exit(&al); > + return ret; > +} > + > // Used when scr->per_event_dump is not set > static struct evsel_script es_stdout; > > @@ -4320,6 +4407,7 @@ int cmd_script(int argc, const char **argv) > > perf_tool__init(&script.tool, !unsorted_dump); > script.tool.sample = process_sample_event; > + script.tool.callchain_deferred = process_deferred_sample_event; > script.tool.mmap = perf_event__process_mmap; > script.tool.mmap2 = perf_event__process_mmap2; > script.tool.comm = perf_event__process_comm; > @@ -4346,6 +4434,7 @@ int cmd_script(int argc, const char **argv) > script.tool.throttle = process_throttle_event; > script.tool.unthrottle = process_throttle_event; > script.tool.ordering_requires_timestamps = true; > + script.tool.merge_deferred_callchains = false; > session = perf_session__new(&data, &script.tool); > if (IS_ERR(session)) > return PTR_ERR(session); > -- > 2.52.0.rc1.455.g30608eb744-goog > >
