Messages in this thread | | | From | Mathieu Poirier <> | Date | Mon, 19 Aug 2019 12:08:26 -0600 | Subject | Re: [PATCH 1/2] perf cs-etm: Support sample flags 'insn' and 'insnlen' |
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On Thu, 15 Aug 2019 at 02:30, Leo Yan <leo.yan@linaro.org> wrote: > > The synthetic branch and instruction samples are missed to set > instruction related info, thus perf tool fails to display samples with > flags '-F,+insn,+insnlen'. > > CoreSight trace decoder has provided sufficient information to decide > the instruction size based on the isa type: A64/A32 instruction are > 32-bit size, but one exception is the T32 instruction size, which might > be 32-bit or 16-bit. > > This patch handles for these cases and it reads the instruction values > from DSO file; thus can support flags '-F,+insn,+insnlen'. > > Before: > > # perf script -F,insn,insnlen,ip,sym > 0 [unknown] ilen: 0 > ffff97174044 _start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > ffff97174938 _dl_start ilen: 0 > > [...] > > After: > > # perf script -F,insn,insnlen,ip,sym > 0 [unknown] ilen: 0 > ffff97174044 _start ilen: 4 insn: 2f 02 00 94 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54 > > [...] > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Cc: Suzuki Poulouse <suzuki.poulose@arm.com> > Cc: Mike Leach <mike.leach@linaro.org> > Cc: Robert Walker <robert.walker@arm.com> > Cc: coresight@lists.linaro.org > Cc: linux-arm-kernel@lists.infradead.org > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > tools/perf/util/cs-etm.c | 35 ++++++++++++++++++++++++++++++++++- > 1 file changed, 34 insertions(+), 1 deletion(-) > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index ed6f7fd5b90b..b3a5daaf1a8f 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -1076,6 +1076,35 @@ bool cs_etm__etmq_is_timeless(struct cs_etm_queue *etmq) > return !!etmq->etm->timeless_decoding; > } > > +static void cs_etm__copy_insn(struct cs_etm_queue *etmq, > + u64 trace_chan_id, > + const struct cs_etm_packet *packet, > + struct perf_sample *sample) > +{ > + /* > + * It's pointless to read instructions for the CS_ETM_DISCONTINUITY > + * packet, so directly bail out with 'insn_len' = 0. > + */ > + if (packet->sample_type == CS_ETM_DISCONTINUITY) { > + sample->insn_len = 0; > + return; > + } > + > + /* > + * T32 instruction size might be 32-bit or 16-bit, decide by calling > + * cs_etm__t32_instr_size(). > + */ > + if (packet->isa == CS_ETM_ISA_T32) > + sample->insn_len = cs_etm__t32_instr_size(etmq, trace_chan_id, > + sample->ip); > + /* Otherwise, A64 and A32 instruction size are always 32-bit. */ > + else > + sample->insn_len = 4; > + > + cs_etm__mem_access(etmq, trace_chan_id, sample->ip, > + sample->insn_len, (void *)sample->insn); > +} > + > static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq, > struct cs_etm_traceid_queue *tidq, > u64 addr, u64 period) > @@ -1097,9 +1126,10 @@ static int cs_etm__synth_instruction_sample(struct cs_etm_queue *etmq, > sample.period = period; > sample.cpu = tidq->packet->cpu; > sample.flags = tidq->prev_packet->flags; > - sample.insn_len = 1; > sample.cpumode = event->sample.header.misc; > > + cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->packet, &sample); > + > if (etm->synth_opts.last_branch) { > cs_etm__copy_last_branch_rb(etmq, tidq); > sample.branch_stack = tidq->last_branch; > @@ -1159,6 +1189,9 @@ static int cs_etm__synth_branch_sample(struct cs_etm_queue *etmq, > sample.flags = tidq->prev_packet->flags; > sample.cpumode = event->sample.header.misc; > > + cs_etm__copy_insn(etmq, tidq->trace_chan_id, tidq->prev_packet, > + &sample); > +
The code seems to be correct. I have also tested this patch.
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> /* > * perf report cannot handle events without a branch stack > */ > -- > 2.17.1 >
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