Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Thu, 16 Apr 2020 12:14:43 -0300 | Subject | Re: [PATCH 11/16] perf intel-pt: Add support for synthesizing callchains for regular events |
| |
Em Wed, Apr 01, 2020 at 01:16:08PM +0300, Adrian Hunter escreveu: > Currently, callchains can be synthesized only for synthesized events. > Support also synthesizing callchains for regular events.
This is super cool, I wonder if we shouldn't do it automatically or just adding a new type of callchains, i.e.:
perf record --call-graph pt uname
Should take care of all the details, i.e. do the extra steps below behind the scenes.
Possibly even find out that the workload specified was built with -fomit-frame-pointers, that the hardware has Intel PT and do all behind the scenes for:
perf record -g uname
Alternatively we could take some less seemingly far fetched approach and make this configurable via:
perf config call-graph.record-mode=pt
What do you think?
- Arnaldo
> Example: > > # perf record --kcore --aux-sample -e '{intel_pt//,cycles}' -c 10000 uname > Linux > [ perf record: Woken up 3 times to write data ] > [ perf record: Captured and wrote 0.532 MB perf.data ] > # perf script --itrace=Ge | head -20 > uname 4864 2419025.358181: 10000 cycles: > ffffffffbba56965 apparmor_bprm_committing_creds+0x35 ([kernel.kallsyms]) > ffffffffbc400cd5 __indirect_thunk_start+0x5 ([kernel.kallsyms]) > ffffffffbba07422 security_bprm_committing_creds+0x22 ([kernel.kallsyms]) > ffffffffbb89805d install_exec_creds+0xd ([kernel.kallsyms]) > ffffffffbb90d9ac load_elf_binary+0x3ac ([kernel.kallsyms]) > > uname 4864 2419025.358185: 10000 cycles: > ffffffffbba56db0 apparmor_bprm_committed_creds+0x20 ([kernel.kallsyms]) > ffffffffbc400cd5 __indirect_thunk_start+0x5 ([kernel.kallsyms]) > ffffffffbba07452 security_bprm_committed_creds+0x22 ([kernel.kallsyms]) > ffffffffbb89809a install_exec_creds+0x4a ([kernel.kallsyms]) > ffffffffbb90d9ac load_elf_binary+0x3ac ([kernel.kallsyms]) > > uname 4864 2419025.358189: 10000 cycles: > ffffffffbb86fdf6 vma_adjust_trans_huge+0x6 ([kernel.kallsyms]) > ffffffffbb821660 __vma_adjust+0x160 ([kernel.kallsyms]) > ffffffffbb897be7 shift_arg_pages+0x97 ([kernel.kallsyms]) > ffffffffbb897ed9 setup_arg_pages+0x1e9 ([kernel.kallsyms]) > ffffffffbb90d9f2 load_elf_binary+0x3f2 ([kernel.kallsyms]) > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > tools/perf/util/intel-pt.c | 68 ++++++++++++++++++++++++++++++++++---- > 1 file changed, 61 insertions(+), 7 deletions(-) > > diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c > index db25c77d82f3..a659b4a1b3f2 100644 > --- a/tools/perf/util/intel-pt.c > +++ b/tools/perf/util/intel-pt.c > @@ -124,6 +124,8 @@ struct intel_pt { > > struct range *time_ranges; > unsigned int range_cnt; > + > + struct ip_callchain *chain; > }; > > enum switch_state { > @@ -868,6 +870,45 @@ static u64 intel_pt_ns_to_ticks(const struct intel_pt *pt, u64 ns) > pt->tc.time_mult; > } > > +static struct ip_callchain *intel_pt_alloc_chain(struct intel_pt *pt) > +{ > + size_t sz = sizeof(struct ip_callchain); > + > + /* Add 1 to callchain_sz for callchain context */ > + sz += (pt->synth_opts.callchain_sz + 1) * sizeof(u64); > + return zalloc(sz); > +} > + > +static int intel_pt_callchain_init(struct intel_pt *pt) > +{ > + struct evsel *evsel; > + > + evlist__for_each_entry(pt->session->evlist, evsel) { > + if (!(evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN)) > + evsel->synth_sample_type |= PERF_SAMPLE_CALLCHAIN; > + } > + > + pt->chain = intel_pt_alloc_chain(pt); > + if (!pt->chain) > + return -ENOMEM; > + > + return 0; > +} > + > +static void intel_pt_add_callchain(struct intel_pt *pt, > + struct perf_sample *sample) > +{ > + struct thread *thread = machine__findnew_thread(pt->machine, > + sample->pid, > + sample->tid); > + > + thread_stack__sample_late(thread, sample->cpu, pt->chain, > + pt->synth_opts.callchain_sz + 1, sample->ip, > + pt->kernel_start); > + > + sample->callchain = pt->chain; > +} > + > static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, > unsigned int queue_nr) > { > @@ -880,11 +921,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, > return NULL; > > if (pt->synth_opts.callchain) { > - size_t sz = sizeof(struct ip_callchain); > - > - /* Add 1 to callchain_sz for callchain context */ > - sz += (pt->synth_opts.callchain_sz + 1) * sizeof(u64); > - ptq->chain = zalloc(sz); > + ptq->chain = intel_pt_alloc_chain(pt); > if (!ptq->chain) > goto out_free; > } > @@ -1992,7 +2029,8 @@ static int intel_pt_sample(struct intel_pt_queue *ptq) > if (!(state->type & INTEL_PT_BRANCH)) > return 0; > > - if (pt->synth_opts.callchain || pt->synth_opts.thread_stack) > + if (pt->synth_opts.callchain || pt->synth_opts.add_callchain || > + pt->synth_opts.thread_stack) > thread_stack__event(ptq->thread, ptq->cpu, ptq->flags, state->from_ip, > state->to_ip, ptq->insn_len, > state->trace_nr); > @@ -2639,6 +2677,11 @@ static int intel_pt_process_event(struct perf_session *session, > if (err) > return err; > > + if (event->header.type == PERF_RECORD_SAMPLE) { > + if (pt->synth_opts.add_callchain && !sample->callchain) > + intel_pt_add_callchain(pt, sample); > + } > + > if (event->header.type == PERF_RECORD_AUX && > (event->aux.flags & PERF_AUX_FLAG_TRUNCATED) && > pt->synth_opts.errors) { > @@ -2710,6 +2753,7 @@ static void intel_pt_free(struct perf_session *session) > session->auxtrace = NULL; > thread__put(pt->unknown_thread); > addr_filters__exit(&pt->filts); > + zfree(&pt->chain); > zfree(&pt->filter); > zfree(&pt->time_ranges); > free(pt); > @@ -3348,6 +3392,7 @@ int intel_pt_process_auxtrace_info(union perf_event *event, > !session->itrace_synth_opts->inject) { > pt->synth_opts.branches = false; > pt->synth_opts.callchain = true; > + pt->synth_opts.add_callchain = true; > } > pt->synth_opts.thread_stack = > session->itrace_synth_opts->thread_stack; > @@ -3380,14 +3425,22 @@ int intel_pt_process_auxtrace_info(union perf_event *event, > pt->branches_filter |= PERF_IP_FLAG_RETURN | > PERF_IP_FLAG_TRACE_BEGIN; > > - if (pt->synth_opts.callchain && !symbol_conf.use_callchain) { > + if ((pt->synth_opts.callchain || pt->synth_opts.add_callchain) && > + !symbol_conf.use_callchain) { > symbol_conf.use_callchain = true; > if (callchain_register_param(&callchain_param) < 0) { > symbol_conf.use_callchain = false; > pt->synth_opts.callchain = false; > + pt->synth_opts.add_callchain = false; > } > } > > + if (pt->synth_opts.add_callchain) { > + err = intel_pt_callchain_init(pt); > + if (err) > + goto err_delete_thread; > + } > + > err = intel_pt_synth_events(pt, session); > if (err) > goto err_delete_thread; > @@ -3410,6 +3463,7 @@ int intel_pt_process_auxtrace_info(union perf_event *event, > return 0; > > err_delete_thread: > + zfree(&pt->chain); > thread__zput(pt->unknown_thread); > err_free_queues: > intel_pt_log_disable(); > -- > 2.17.1 >
--
- Arnaldo
| |