Messages in this thread | | | Date | Wed, 31 Oct 2018 11:26:47 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 4/5] perf intel-pt: Insert callchain context into synthesized callchains |
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Em Wed, Oct 31, 2018 at 04:15:26PM +0200, Adrian Hunter escreveu: > On 31/10/18 3:28 PM, Arnaldo Carvalho de Melo wrote: > > Em Wed, Oct 31, 2018 at 11:10:42AM +0200, Adrian Hunter escreveu: > >> In the absence of a fallback, callchains must encode also the callchain > >> context. Do that now there is no fallback. > > > > So, this one is independent of the first 3 patches, right? > > Yes. I was just going to test it separately when I noticed I had > screwed up my earlier testing. When I re-tested I discovered this patch > has an off-by-one error: > > diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c > index afdf36852ac8..61a4286a74dc 100644 > --- a/tools/perf/util/thread-stack.c > +++ b/tools/perf/util/thread-stack.c > @@ -337,7 +337,7 @@ void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, > > last_context = context; > > - for (i = 2, j = 0; i < sz && j < thread->ts->cnt; i++, j++) { > + for (i = 2, j = 1; i < sz && j <= thread->ts->cnt; i++, j++) { > ip = thread->ts->stack[thread->ts->cnt - j].ret_addr; > context = callchain_context(ip, kernel_start); > if (context != last_context) { > > Shall I send V2?
No need, I can fix this here
> > So, this one is independent of the first 3 patches, right? Ok, applying > > it first, I'll relook the first ones next. > > > > - Arnaldo > > > >> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > >> Cc: stable@vger.kernel.org # 4.19 > >> --- > >> tools/perf/util/intel-pt.c | 6 +++-- > >> tools/perf/util/thread-stack.c | 44 +++++++++++++++++++++++++++------- > >> tools/perf/util/thread-stack.h | 2 +- > >> 3 files changed, 40 insertions(+), 12 deletions(-) > >> > >> diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c > >> index ffa385a029b3..60732213d16a 100644 > >> --- a/tools/perf/util/intel-pt.c > >> +++ b/tools/perf/util/intel-pt.c > >> @@ -759,7 +759,8 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, > >> if (pt->synth_opts.callchain) { > >> size_t sz = sizeof(struct ip_callchain); > >> > >> - sz += pt->synth_opts.callchain_sz * sizeof(u64); > >> + /* Add 1 to callchain_sz for callchain context */ > >> + sz += (pt->synth_opts.callchain_sz + 1) * sizeof(u64); > >> ptq->chain = zalloc(sz); > >> if (!ptq->chain) > >> goto out_free; > >> @@ -1160,7 +1161,8 @@ static void intel_pt_prep_sample(struct intel_pt *pt, > >> > >> if (pt->synth_opts.callchain) { > >> thread_stack__sample(ptq->thread, ptq->chain, > >> - pt->synth_opts.callchain_sz, sample->ip); > >> + pt->synth_opts.callchain_sz + 1, > >> + sample->ip, pt->kernel_start); > >> sample->callchain = ptq->chain; > >> } > >> > >> diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c > >> index c091635bf7dc..afdf36852ac8 100644 > >> --- a/tools/perf/util/thread-stack.c > >> +++ b/tools/perf/util/thread-stack.c > >> @@ -310,20 +310,46 @@ void thread_stack__free(struct thread *thread) > >> } > >> } > >> > >> +static inline u64 callchain_context(u64 ip, u64 kernel_start) > >> +{ > >> + return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL; > >> +} > >> + > >> void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, > >> - size_t sz, u64 ip) > >> + size_t sz, u64 ip, u64 kernel_start) > >> { > >> - size_t i; > >> + u64 context = callchain_context(ip, kernel_start); > >> + u64 last_context; > >> + size_t i, j; > >> > >> - if (!thread || !thread->ts) > >> - chain->nr = 1; > >> - else > >> - chain->nr = min(sz, thread->ts->cnt + 1); > >> + if (sz < 2) { > >> + chain->nr = 0; > >> + return; > >> + } > >> > >> - chain->ips[0] = ip; > >> + chain->ips[0] = context; > >> + chain->ips[1] = ip; > >> + > >> + if (!thread || !thread->ts) { > >> + chain->nr = 2; > >> + return; > >> + } > >> + > >> + last_context = context; > >> + > >> + for (i = 2, j = 0; i < sz && j < thread->ts->cnt; i++, j++) { > >> + ip = thread->ts->stack[thread->ts->cnt - j].ret_addr; > >> + context = callchain_context(ip, kernel_start); > >> + if (context != last_context) { > >> + if (i >= sz - 1) > >> + break; > >> + chain->ips[i++] = context; > >> + last_context = context; > >> + } > >> + chain->ips[i] = ip; > >> + } > >> > >> - for (i = 1; i < chain->nr; i++) > >> - chain->ips[i] = thread->ts->stack[thread->ts->cnt - i].ret_addr; > >> + chain->nr = i; > >> } > >> > >> struct call_return_processor * > >> diff --git a/tools/perf/util/thread-stack.h b/tools/perf/util/thread-stack.h > >> index b7e41c4ebfdd..f97c00a8c251 100644 > >> --- a/tools/perf/util/thread-stack.h > >> +++ b/tools/perf/util/thread-stack.h > >> @@ -84,7 +84,7 @@ int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip, > >> u64 to_ip, u16 insn_len, u64 trace_nr); > >> void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr); > >> void thread_stack__sample(struct thread *thread, struct ip_callchain *chain, > >> - size_t sz, u64 ip); > >> + size_t sz, u64 ip, u64 kernel_start); > >> int thread_stack__flush(struct thread *thread); > >> void thread_stack__free(struct thread *thread); > >> size_t thread_stack__depth(struct thread *thread); > >> -- > >> 2.17.1 > >
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