perf script: Display PERF_RECORD_CALLCHAIN_DEFERRED

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 (cookie) ([unknown])

  pwd    2312   121.163447: DEFERRED CALLCHAIN [cookie: b00000006]
              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)

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
This commit is contained in:
Namhyung Kim
2025-11-20 15:48:02 -08:00
parent 27ddc1d7a6
commit 25a9dd56cf
2 changed files with 93 additions and 1 deletions

View File

@@ -2706,6 +2706,94 @@ 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 [cookie: %llx]",
(unsigned long long)event->callchain_deferred.cookie);
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;
@@ -4303,6 +4391,7 @@ 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;

View File

@@ -168,7 +168,10 @@ int sample__fprintf_callchain(struct perf_sample *sample, int left_alignment,
node_al.addr = addr;
node_al.map = map__get(map);
if (print_symoffset) {
if (sample->deferred_callchain &&
sample->deferred_cookie == node->ip) {
printed += fprintf(fp, "(cookie)");
} else if (print_symoffset) {
printed += __symbol__fprintf_symname_offs(sym, &node_al,
print_unknown_as_addr,
true, fp);