Messages in this thread | | | Date | Fri, 11 Oct 2019 13:59:28 -0600 | From | Mathieu Poirier <> | Subject | Re: [PATCH v3 5/6] perf cs-etm: Support callchain for instruction sample |
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On Sat, Oct 05, 2019 at 05:16:13PM +0800, Leo Yan wrote: > Now CoreSight has supported the thread stack; based on the thread stack > we can synthesize call chain for the instruction sample; the call chain > can be injected by option '--itrace=g'. > > Before: > > # perf script --itrace=g16l64i100 > main 1579 100 instructions: ffff0000102137f0 group_sched_in+0xb0 ([kernel.kallsyms]) > main 1579 100 instructions: ffff000010213b78 flexible_sched_in+0xf0 ([kernel.kallsyms]) > main 1579 100 instructions: ffff0000102135ac event_sched_in.isra.57+0x74 ([kernel.kallsyms]) > main 1579 100 instructions: ffff000010219344 perf_swevent_add+0x6c ([kernel.kallsyms]) > main 1579 100 instructions: ffff000010214854 perf_event_update_userpage+0x4c ([kernel.kallsyms]) > [...] > > After: > > # perf script --itrace=g16l64i100 > > main 1579 100 instructions: > ffff000010213b78 flexible_sched_in+0xf0 ([kernel.kallsyms]) > ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms]) > > main 1579 100 instructions: > ffff0000102135ac event_sched_in.isra.57+0x74 ([kernel.kallsyms]) > ffff0000102137a0 group_sched_in+0x60 ([kernel.kallsyms]) > ffff000010213b84 flexible_sched_in+0xfc ([kernel.kallsyms]) > ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms]) > > main 1579 100 instructions: > ffff000010219344 perf_swevent_add+0x6c ([kernel.kallsyms]) > ffff0000102135f4 event_sched_in.isra.57+0xbc ([kernel.kallsyms]) > ffff0000102137a0 group_sched_in+0x60 ([kernel.kallsyms]) > ffff000010213b84 flexible_sched_in+0xfc ([kernel.kallsyms]) > ffff00001020c0b4 visit_groups_merge+0x12c ([kernel.kallsyms]) > [...] > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/cs-etm.c | 35 +++++++++++++++++++++++++++++++++-- > 1 file changed, 33 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index 4b42f9c9bd34..56e501cd2f5f 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -17,6 +17,7 @@ > #include <stdlib.h> > > #include "auxtrace.h" > +#include "callchain.h" > #include "color.h" > #include "cs-etm.h" > #include "cs-etm-decoder/cs-etm-decoder.h" > @@ -74,6 +75,7 @@ struct cs_etm_traceid_queue { > size_t last_branch_pos; > union perf_event *event_buf; > struct thread *thread; > + struct ip_callchain *chain; > struct branch_stack *last_branch; > struct branch_stack *last_branch_rb; > struct cs_etm_packet *prev_packet; > @@ -251,6 +253,16 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq, > if (!tidq->prev_packet) > goto out_free; > > + if (etm->synth_opts.callchain) { > + size_t sz = sizeof(struct ip_callchain); > + > + /* Add 1 to callchain_sz for callchain context */ > + sz += (etm->synth_opts.callchain_sz + 1) * sizeof(u64); > + tidq->chain = zalloc(sz); > + if (!tidq->chain) > + goto out_free; > + } > + > if (etm->synth_opts.last_branch) { > size_t sz = sizeof(struct branch_stack); > > @@ -275,6 +287,7 @@ static int cs_etm__init_traceid_queue(struct cs_etm_queue *etmq, > zfree(&tidq->last_branch); > zfree(&tidq->prev_packet); > zfree(&tidq->packet); > + zfree(&tidq->chain);
Theoretically this should go two lines up, i.e just below zfree(&tidq->prev_packet). If you agree with the comment I did in 3/6 then it is worth doing the above change, otherwise it can stay that way.
> out: > return rc; > } > @@ -546,6 +559,7 @@ static void cs_etm__free_traceid_queues(struct cs_etm_queue *etmq) > zfree(&tidq->last_branch_rb); > zfree(&tidq->prev_packet); > zfree(&tidq->packet); > + zfree(&tidq->chain);
Same comment as above. The rest looks good to me.
Mathieu
> zfree(&tidq); > > /* > @@ -1126,7 +1140,7 @@ static void cs_etm__add_stack_event(struct cs_etm_queue *etmq, > int insn_len; > u64 from_ip, to_ip; > > - if (etm->synth_opts.thread_stack) { > + if (etm->synth_opts.callchain || etm->synth_opts.thread_stack) { > from_ip = cs_etm__last_executed_instr(tidq->prev_packet); > to_ip = cs_etm__first_executed_instr(tidq->packet); > > @@ -1182,6 +1196,14 @@ static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq, > > cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->packet, &sample); > > + if (etm->synth_opts.callchain) { > + thread_stack__sample(tidq->thread, tidq->packet->cpu, > + tidq->chain, > + etm->synth_opts.callchain_sz + 1, > + sample.ip, etm->kernel_start); > + sample.callchain = tidq->chain; > + } > + > if (etm->synth_opts.last_branch) { > cs_etm__copy_last_branch_rb(etmq, tidq); > sample.branch_stack = tidq->last_branch; > @@ -1369,6 +1391,8 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm, > attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR; > } > > + if (etm->synth_opts.callchain) > + attr.sample_type |= PERF_SAMPLE_CALLCHAIN; > if (etm->synth_opts.last_branch) > attr.sample_type |= PERF_SAMPLE_BRANCH_STACK; > > @@ -2639,7 +2663,6 @@ int cs_etm__process_auxtrace_info(union perf_event *event, > } else { > itrace_synth_opts__set_default(&etm->synth_opts, > session->itrace_synth_opts->default_no_sample); > - etm->synth_opts.callchain = false; > etm->synth_opts.thread_stack = > session->itrace_synth_opts->thread_stack; > } > @@ -2651,6 +2674,14 @@ int cs_etm__process_auxtrace_info(union perf_event *event, > etm->branches_filter |= PERF_IP_FLAG_RETURN | > PERF_IP_FLAG_TRACE_BEGIN; > > + if (etm->synth_opts.callchain && !symbol_conf.use_callchain) { > + symbol_conf.use_callchain = true; > + if (callchain_register_param(&callchain_param) < 0) { > + symbol_conf.use_callchain = false; > + etm->synth_opts.callchain = false; > + } > + } > + > err = cs_etm__synth_events(etm, session); > if (err) > goto err_delete_thread; > -- > 2.17.1 >
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