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perf intel-pt: Add support for synthesizing branch stacks for regular events 

Use the new thread_stack__br_sample_late() function to create a thread
stack for regular events.

Example:

 # perf record --kcore --aux-sample -e '{intel_pt//,cycles:ppp}' -c 10000 uname
 Linux
 [ perf record: Woken up 2 times to write data ]
 [ perf record: Captured and wrote 0.743 MB perf.data ]
 # perf report --itrace=Le --stdio | head -30 | tail -18

 # Samples: 11K of event 'cycles:ppp'
 # Event count (approx.): 11648
 #
 # Overhead  Command  Source Shared Object  Source Symbol                 Target Symbol                 Basic Block Cycles
 # ........  .......  ....................  ............................  ............................  ..................
 #
      5.49%  uname    libc-2.30.so          [.] _dl_addr                  [.] _dl_addr                  -
      2.41%  uname    ld-2.30.so            [.] _dl_relocate_object       [.] _dl_relocate_object       -
      2.31%  uname    ld-2.30.so            [.] do_lookup_x               [.] do_lookup_x               -
      2.17%  uname    [kernel.kallsyms]     [k] unmap_page_range          [k] unmap_page_range          -
      2.05%  uname    ld-2.30.so            [k] _dl_start                 [k] _dl_start                 -
      1.97%  uname    ld-2.30.so            [.] _dl_lookup_symbol_x       [.] _dl_lookup_symbol_x       -
      1.94%  uname    [kernel.kallsyms]     [k] filemap_map_pages         [k] filemap_map_pages         -
      1.60%  uname    [kernel.kallsyms]     [k] __handle_mm_fault         [k] __handle_mm_fault         -
      1.44%  uname    [kernel.kallsyms]     [k] page_add_file_rmap        [k] page_add_file_rmap        -
      1.12%  uname    [kernel.kallsyms]     [k] vma_interval_tree_insert  [k] vma_interval_tree_insert  -
      0.94%  uname    [kernel.kallsyms]     [k] perf_iterate_ctx          [k] perf_iterate_ctx          -

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200429150751.12570-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2020-04-29 18:07:49 +03:00 committed by Arnaldo Carvalho de Melo
parent 3749e0bbde
commit f0a0251cee
1 changed files with 66 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
tools/perf/util/intel-pt.c
View File

@ -72,6 +72,7 @@ struct intel_pt {
bool use_thread_stack;
bool callstack;
unsigned int br_stack_sz;
unsigned int br_stack_sz_plus;
int have_sched_switch;
u32 pmu_type;
u64 kernel_start;
@ -130,6 +131,7 @@ struct intel_pt {
unsigned int range_cnt;
struct ip_callchain *chain;
struct branch_stack *br_stack;
};
enum switch_state {
@ -911,6 +913,44 @@ static void intel_pt_add_callchain(struct intel_pt *pt,
sample->callchain = pt->chain;
}
static struct branch_stack *intel_pt_alloc_br_stack(struct intel_pt *pt)
{
size_t sz = sizeof(struct branch_stack);
sz += pt->br_stack_sz * sizeof(struct branch_entry);
return zalloc(sz);
}
static int intel_pt_br_stack_init(struct intel_pt *pt)
{
struct evsel *evsel;
evlist__for_each_entry(pt->session->evlist, evsel) {
if (!(evsel->core.attr.sample_type & PERF_SAMPLE_BRANCH_STACK))
evsel->synth_sample_type |= PERF_SAMPLE_BRANCH_STACK;
}
pt->br_stack = intel_pt_alloc_br_stack(pt);
if (!pt->br_stack)
return -ENOMEM;
return 0;
}
static void intel_pt_add_br_stack(struct intel_pt *pt,
struct perf_sample *sample)
{
struct thread *thread = machine__findnew_thread(pt->machine,
sample->pid,
sample->tid);
thread_stack__br_sample_late(thread, sample->cpu, pt->br_stack,
pt->br_stack_sz, sample->ip,
pt->kernel_start);
sample->branch_stack = pt->br_stack;
}
static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
unsigned int queue_nr)
{
@ -929,10 +969,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
}
if (pt->synth_opts.last_branch) {
size_t sz = sizeof(struct branch_stack);
sz += pt->br_stack_sz * sizeof(struct branch_entry);
ptq->last_branch = zalloc(sz);
ptq->last_branch = intel_pt_alloc_br_stack(pt);
if (!ptq->last_branch)
goto out_free;
}
@ -1963,7 +2000,7 @@ static int intel_pt_sample(struct intel_pt_queue *ptq)
thread_stack__event(ptq->thread, ptq->cpu, ptq->flags,
state->from_ip, state->to_ip, ptq->insn_len,
state->trace_nr, pt->callstack,
pt->br_stack_sz,
pt->br_stack_sz_plus,
pt->mispred_all);
} else {
thread_stack__set_trace_nr(ptq->thread, ptq->cpu, state->trace_nr);
@ -2609,6 +2646,8 @@ static int intel_pt_process_event(struct perf_session *session,
if (event->header.type == PERF_RECORD_SAMPLE) {
if (pt->synth_opts.add_callchain && !sample->callchain)
intel_pt_add_callchain(pt, sample);
if (pt->synth_opts.add_last_branch && !sample->branch_stack)
intel_pt_add_br_stack(pt, sample);
}
if (event->header.type == PERF_RECORD_AUX &&
@ -3370,13 +3409,33 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
goto err_delete_thread;
}
if (pt->synth_opts.last_branch)
if (pt->synth_opts.last_branch || pt->synth_opts.add_last_branch) {
pt->br_stack_sz = pt->synth_opts.last_branch_sz;
pt->br_stack_sz_plus = pt->br_stack_sz;
}
if (pt->synth_opts.add_last_branch) {
err = intel_pt_br_stack_init(pt);
if (err)
goto err_delete_thread;
/*
* Additional branch stack size to cater for tracing from the
* actual sample ip to where the sample time is recorded.
* Measured at about 200 branches, but generously set to 1024.
* If kernel space is not being traced, then add just 1 for the
* branch to kernel space.
*/
if (intel_pt_tracing_kernel(pt))
pt->br_stack_sz_plus += 1024;
else
pt->br_stack_sz_plus += 1;
}
pt->use_thread_stack = pt->synth_opts.callchain ||
pt->synth_opts.add_callchain ||
pt->synth_opts.thread_stack ||
pt->synth_opts.last_branch;
pt->synth_opts.last_branch ||
pt->synth_opts.add_last_branch;
pt->callstack = pt->synth_opts.callchain ||
pt->synth_opts.add_callchain ||