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perf callchain: Per-event type selection support

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This patchkit adds the ability to set callgraph mode (fp, dwarf, lbr) per
event. This in term can reduce sampling overhead and the size of the
perf.data.

Here is an example.

  perf record -e 'cpu/cpu-cycles,period=1000,call-graph=fp,time=1/,cpu/instructions,call-graph=lbr/' sleep 1

 perf evlist -v
 cpu/cpu-cycles,period=1000,call-graph=fp,time=1/: type: 4, size: 112,
 config: 0x3c, { sample_period, sample_freq }: 1000, sample_type:
 IP|TID|TIME|CALLCHAIN|PERIOD|IDENTIFIER, read_format: ID, disabled: 1,
 inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all:
 1, exclude_guest: 1, mmap2: 1, comm_exec: 1
 cpu/instructions,call-graph=lbr/: type: 4, size: 112, config: 0xc0, {
 sample_period, sample_freq }: 4000, sample_type:
 IP|TID|TIME|CALLCHAIN|PERIOD|BRANCH_STACK|IDENTIFIER, read_format: ID,
 disabled: 1, inherit: 1, freq: 1, enable_on_exec: 1, sample_id_all: 1,
 exclude_guest: 1

Signed-off-by: Kan Liang <kan.liang@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1439289050-40510-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Kan Liang
2015-08-11 06:30:47 -04:00
committed by Arnaldo Carvalho de Melo
parent 75186a9b09
commit d457c96392
7 changed files with 86 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

62
tools/perf/util/evsel.c
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@@ -588,11 +588,36 @@ perf_evsel__config_callgraph(struct perf_evsel *evsel,
}
}
static void apply_config_terms(struct perf_evsel *evsel)
static void
perf_evsel__reset_callgraph(struct perf_evsel *evsel,
struct callchain_param *param)
{
struct perf_event_attr *attr = &evsel->attr;
perf_evsel__reset_sample_bit(evsel, CALLCHAIN);
if (param->record_mode == CALLCHAIN_LBR) {
perf_evsel__reset_sample_bit(evsel, BRANCH_STACK);
attr->branch_sample_type &= ~(PERF_SAMPLE_BRANCH_USER |
PERF_SAMPLE_BRANCH_CALL_STACK);
}
if (param->record_mode == CALLCHAIN_DWARF) {
perf_evsel__reset_sample_bit(evsel, REGS_USER);
perf_evsel__reset_sample_bit(evsel, STACK_USER);
}
}
static void apply_config_terms(struct perf_evsel *evsel,
struct record_opts *opts)
{
struct perf_evsel_config_term *term;
struct list_head *config_terms = &evsel->config_terms;
struct perf_event_attr *attr = &evsel->attr;
struct callchain_param param;
u32 dump_size = 0;
char *callgraph_buf = NULL;
/* callgraph default */
param.record_mode = callchain_param.record_mode;
list_for_each_entry(term, config_terms, list) {
switch (term->type) {
@@ -610,10 +635,43 @@ static void apply_config_terms(struct perf_evsel *evsel)
else
perf_evsel__reset_sample_bit(evsel, TIME);
break;
case PERF_EVSEL__CONFIG_TERM_CALLGRAPH:
callgraph_buf = term->val.callgraph;
break;
case PERF_EVSEL__CONFIG_TERM_STACK_USER:
dump_size = term->val.stack_user;
break;
default:
break;
}
}
/* User explicitly set per-event callgraph, clear the old setting and reset. */
if ((callgraph_buf != NULL) || (dump_size > 0)) {
/* parse callgraph parameters */
if (callgraph_buf != NULL) {
param.enabled = true;
if (parse_callchain_record(callgraph_buf, &param)) {
pr_err("per-event callgraph setting for %s failed. "
"Apply callgraph global setting for it\n",
evsel->name);
return;
}
}
if (dump_size > 0) {
dump_size = round_up(dump_size, sizeof(u64));
param.dump_size = dump_size;
}
/* If global callgraph set, clear it */
if (callchain_param.enabled)
perf_evsel__reset_callgraph(evsel, &callchain_param);
/* set perf-event callgraph */
if (param.enabled)
perf_evsel__config_callgraph(evsel, opts, &param);
}
}
/*
@@ -812,7 +870,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts)
* Apply event specific term settings,
* it overloads any global configuration.
*/
apply_config_terms(evsel);
apply_config_terms(evsel, opts);
}
static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)