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? > 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.hun...@intel.com> >> Cc: sta...@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 >