perf intel-pt: Add support for PERF_RECORD_SWITCH
Add support for selecting and processing PERF_RECORD_SWITCH events for use by Intel PT. If they are available, they will be used in preference to sched_switch events. This enables an unprivileged user to trace multi-threaded or multi-process workloads with any level of perf_event_paranoid. However it depends on kernel support for PERF_RECORD_SWITCH. Without this patch, tracing a multi-threaded workload will decode without error but all the data will be attributed to the main thread. Without this patch, tracing a multi-process workload will result in decoder errors because the decoder will not know which executable is executing. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Link: http://lkml.kernel.org/r/1439458857-30636-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>hifive-unleashed-5.1
Adrian Hunter
Arnaldo Carvalho de Melo
parent
1b29ac59b1
commit
86c2786994
|
|
@ -624,13 +624,49 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
|
|||
* threads.
|
||||
*/
|
||||
if (have_timing_info && !cpu_map__empty(cpus)) {
|
||||
err = intel_pt_track_switches(evlist);
|
||||
if (err == -EPERM)
|
||||
pr_debug2("Unable to select sched:sched_switch\n");
|
||||
else if (err)
|
||||
return err;
|
||||
else
|
||||
ptr->have_sched_switch = 1;
|
||||
if (perf_can_record_switch_events()) {
|
||||
bool cpu_wide = !target__none(&opts->target) &&
|
||||
!target__has_task(&opts->target);
|
||||
|
||||
if (!cpu_wide && perf_can_record_cpu_wide()) {
|
||||
struct perf_evsel *switch_evsel;
|
||||
|
||||
err = parse_events(evlist, "dummy:u", NULL);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
switch_evsel = perf_evlist__last(evlist);
|
||||
|
||||
switch_evsel->attr.freq = 0;
|
||||
switch_evsel->attr.sample_period = 1;
|
||||
switch_evsel->attr.context_switch = 1;
|
||||
|
||||
switch_evsel->system_wide = true;
|
||||
switch_evsel->no_aux_samples = true;
|
||||
switch_evsel->immediate = true;
|
||||
|
||||
perf_evsel__set_sample_bit(switch_evsel, TID);
|
||||
perf_evsel__set_sample_bit(switch_evsel, TIME);
|
||||
perf_evsel__set_sample_bit(switch_evsel, CPU);
|
||||
|
||||
opts->record_switch_events = false;
|
||||
ptr->have_sched_switch = 3;
|
||||
} else {
|
||||
opts->record_switch_events = true;
|
||||
if (cpu_wide)
|
||||
ptr->have_sched_switch = 3;
|
||||
else
|
||||
ptr->have_sched_switch = 2;
|
||||
}
|
||||
} else {
|
||||
err = intel_pt_track_switches(evlist);
|
||||
if (err == -EPERM)
|
||||
pr_debug2("Unable to select sched:sched_switch\n");
|
||||
else if (err)
|
||||
return err;
|
||||
else
|
||||
ptr->have_sched_switch = 1;
|
||||
}
|
||||
}
|
||||
|
||||
if (intel_pt_evsel) {
|
||||
|
|
@ -663,8 +699,11 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
|
|||
tracking_evsel->attr.sample_period = 1;
|
||||
|
||||
/* In per-cpu case, always need the time of mmap events etc */
|
||||
if (!cpu_map__empty(cpus))
|
||||
if (!cpu_map__empty(cpus)) {
|
||||
perf_evsel__set_sample_bit(tracking_evsel, TIME);
|
||||
/* And the CPU for switch events */
|
||||
perf_evsel__set_sample_bit(tracking_evsel, CPU);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
|
|||
|
|
@ -1145,11 +1145,13 @@ static int intel_pt_sample(struct intel_pt_queue *ptq)
|
|||
return 0;
|
||||
}
|
||||
|
||||
static u64 intel_pt_switch_ip(struct machine *machine, u64 *ptss_ip)
|
||||
static u64 intel_pt_switch_ip(struct intel_pt *pt, u64 *ptss_ip)
|
||||
{
|
||||
struct machine *machine = pt->machine;
|
||||
struct map *map;
|
||||
struct symbol *sym, *start;
|
||||
u64 ip, switch_ip = 0;
|
||||
const char *ptss;
|
||||
|
||||
if (ptss_ip)
|
||||
*ptss_ip = 0;
|
||||
|
|
@ -1177,8 +1179,13 @@ static u64 intel_pt_switch_ip(struct machine *machine, u64 *ptss_ip)
|
|||
if (!switch_ip || !ptss_ip)
|
||||
return 0;
|
||||
|
||||
if (pt->have_sched_switch == 1)
|
||||
ptss = "perf_trace_sched_switch";
|
||||
else
|
||||
ptss = "__perf_event_task_sched_out";
|
||||
|
||||
for (sym = start; sym; sym = dso__next_symbol(sym)) {
|
||||
if (!strcmp(sym->name, "perf_trace_sched_switch")) {
|
||||
if (!strcmp(sym->name, ptss)) {
|
||||
ip = map->unmap_ip(map, sym->start);
|
||||
if (ip >= map->start && ip < map->end) {
|
||||
*ptss_ip = ip;
|
||||
|
|
@ -1198,11 +1205,11 @@ static int intel_pt_run_decoder(struct intel_pt_queue *ptq, u64 *timestamp)
|
|||
|
||||
if (!pt->kernel_start) {
|
||||
pt->kernel_start = machine__kernel_start(pt->machine);
|
||||
if (pt->per_cpu_mmaps && pt->have_sched_switch &&
|
||||
if (pt->per_cpu_mmaps &&
|
||||
(pt->have_sched_switch == 1 || pt->have_sched_switch == 3) &&
|
||||
!pt->timeless_decoding && intel_pt_tracing_kernel(pt) &&
|
||||
!pt->sampling_mode) {
|
||||
pt->switch_ip = intel_pt_switch_ip(pt->machine,
|
||||
&pt->ptss_ip);
|
||||
pt->switch_ip = intel_pt_switch_ip(pt, &pt->ptss_ip);
|
||||
if (pt->switch_ip) {
|
||||
intel_pt_log("switch_ip: %"PRIx64" ptss_ip: %"PRIx64"\n",
|
||||
pt->switch_ip, pt->ptss_ip);
|
||||
|
|
@ -1387,31 +1394,18 @@ static struct intel_pt_queue *intel_pt_cpu_to_ptq(struct intel_pt *pt, int cpu)
|
|||
return NULL;
|
||||
}
|
||||
|
||||
static int intel_pt_process_switch(struct intel_pt *pt,
|
||||
struct perf_sample *sample)
|
||||
static int intel_pt_sync_switch(struct intel_pt *pt, int cpu, pid_t tid,
|
||||
u64 timestamp)
|
||||
{
|
||||
struct intel_pt_queue *ptq;
|
||||
struct perf_evsel *evsel;
|
||||
pid_t tid;
|
||||
int cpu, err;
|
||||
|
||||
evsel = perf_evlist__id2evsel(pt->session->evlist, sample->id);
|
||||
if (evsel != pt->switch_evsel)
|
||||
return 0;
|
||||
|
||||
tid = perf_evsel__intval(evsel, sample, "next_pid");
|
||||
cpu = sample->cpu;
|
||||
|
||||
intel_pt_log("sched_switch: cpu %d tid %d time %"PRIu64" tsc %#"PRIx64"\n",
|
||||
cpu, tid, sample->time, perf_time_to_tsc(sample->time,
|
||||
&pt->tc));
|
||||
int err;
|
||||
|
||||
if (!pt->sync_switch)
|
||||
goto out;
|
||||
return 1;
|
||||
|
||||
ptq = intel_pt_cpu_to_ptq(pt, cpu);
|
||||
if (!ptq)
|
||||
goto out;
|
||||
return 1;
|
||||
|
||||
switch (ptq->switch_state) {
|
||||
case INTEL_PT_SS_NOT_TRACING:
|
||||
|
|
@ -1424,7 +1418,7 @@ static int intel_pt_process_switch(struct intel_pt *pt,
|
|||
return 0;
|
||||
case INTEL_PT_SS_EXPECTING_SWITCH_EVENT:
|
||||
if (!ptq->on_heap) {
|
||||
ptq->timestamp = perf_time_to_tsc(sample->time,
|
||||
ptq->timestamp = perf_time_to_tsc(timestamp,
|
||||
&pt->tc);
|
||||
err = auxtrace_heap__add(&pt->heap, ptq->queue_nr,
|
||||
ptq->timestamp);
|
||||
|
|
@ -1441,10 +1435,76 @@ static int intel_pt_process_switch(struct intel_pt *pt,
|
|||
default:
|
||||
break;
|
||||
}
|
||||
out:
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static int intel_pt_process_switch(struct intel_pt *pt,
|
||||
struct perf_sample *sample)
|
||||
{
|
||||
struct perf_evsel *evsel;
|
||||
pid_t tid;
|
||||
int cpu, ret;
|
||||
|
||||
evsel = perf_evlist__id2evsel(pt->session->evlist, sample->id);
|
||||
if (evsel != pt->switch_evsel)
|
||||
return 0;
|
||||
|
||||
tid = perf_evsel__intval(evsel, sample, "next_pid");
|
||||
cpu = sample->cpu;
|
||||
|
||||
intel_pt_log("sched_switch: cpu %d tid %d time %"PRIu64" tsc %#"PRIx64"\n",
|
||||
cpu, tid, sample->time, perf_time_to_tsc(sample->time,
|
||||
&pt->tc));
|
||||
|
||||
ret = intel_pt_sync_switch(pt, cpu, tid, sample->time);
|
||||
if (ret <= 0)
|
||||
return ret;
|
||||
|
||||
return machine__set_current_tid(pt->machine, cpu, -1, tid);
|
||||
}
|
||||
|
||||
static int intel_pt_context_switch(struct intel_pt *pt, union perf_event *event,
|
||||
struct perf_sample *sample)
|
||||
{
|
||||
bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;
|
||||
pid_t pid, tid;
|
||||
int cpu, ret;
|
||||
|
||||
cpu = sample->cpu;
|
||||
|
||||
if (pt->have_sched_switch == 3) {
|
||||
if (!out)
|
||||
return 0;
|
||||
if (event->header.type != PERF_RECORD_SWITCH_CPU_WIDE) {
|
||||
pr_err("Expecting CPU-wide context switch event\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
pid = event->context_switch.next_prev_pid;
|
||||
tid = event->context_switch.next_prev_tid;
|
||||
} else {
|
||||
if (out)
|
||||
return 0;
|
||||
pid = sample->pid;
|
||||
tid = sample->tid;
|
||||
}
|
||||
|
||||
if (tid == -1) {
|
||||
pr_err("context_switch event has no tid\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
intel_pt_log("context_switch: cpu %d pid %d tid %d time %"PRIu64" tsc %#"PRIx64"\n",
|
||||
cpu, pid, tid, sample->time, perf_time_to_tsc(sample->time,
|
||||
&pt->tc));
|
||||
|
||||
ret = intel_pt_sync_switch(pt, cpu, tid, sample->time);
|
||||
if (ret <= 0)
|
||||
return ret;
|
||||
|
||||
return machine__set_current_tid(pt->machine, cpu, pid, tid);
|
||||
}
|
||||
|
||||
static int intel_pt_process_itrace_start(struct intel_pt *pt,
|
||||
union perf_event *event,
|
||||
struct perf_sample *sample)
|
||||
|
|
@ -1515,6 +1575,9 @@ static int intel_pt_process_event(struct perf_session *session,
|
|||
err = intel_pt_process_switch(pt, sample);
|
||||
else if (event->header.type == PERF_RECORD_ITRACE_START)
|
||||
err = intel_pt_process_itrace_start(pt, event, sample);
|
||||
else if (event->header.type == PERF_RECORD_SWITCH ||
|
||||
event->header.type == PERF_RECORD_SWITCH_CPU_WIDE)
|
||||
err = intel_pt_context_switch(pt, event, sample);
|
||||
|
||||
intel_pt_log("event %s (%u): cpu %d time %"PRIu64" tsc %#"PRIx64"\n",
|
||||
perf_event__name(event->header.type), event->header.type,
|
||||
|
|
@ -1777,6 +1840,18 @@ static struct perf_evsel *intel_pt_find_sched_switch(struct perf_evlist *evlist)
|
|||
return NULL;
|
||||
}
|
||||
|
||||
static bool intel_pt_find_switch(struct perf_evlist *evlist)
|
||||
{
|
||||
struct perf_evsel *evsel;
|
||||
|
||||
evlist__for_each(evlist, evsel) {
|
||||
if (evsel->attr.context_switch)
|
||||
return true;
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
static const char * const intel_pt_info_fmts[] = {
|
||||
[INTEL_PT_PMU_TYPE] = " PMU Type %"PRId64"\n",
|
||||
[INTEL_PT_TIME_SHIFT] = " Time Shift %"PRIu64"\n",
|
||||
|
|
@ -1888,6 +1963,10 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
|
|||
pr_err("%s: missing sched_switch event\n", __func__);
|
||||
goto err_delete_thread;
|
||||
}
|
||||
} else if (pt->have_sched_switch == 2 &&
|
||||
!intel_pt_find_switch(session->evlist)) {
|
||||
pr_err("%s: missing context_switch attribute flag\n", __func__);
|
||||
goto err_delete_thread;
|
||||
}
|
||||
|
||||
if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
|
||||
|
|
|
|||
Loading…
Reference in New Issue