Commit d457c963 authored by Kan Liang's avatar Kan Liang Committed by Arnaldo Carvalho de Melo
Browse files

perf callchain: Per-event type selection support 



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: default avatarKan Liang <kan.liang@intel.com>
Tested-by: default avatarArnaldo 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 75186a9b

tools/perf/Documentation/perf-record.txt

+3 −0
Original line number Diff line number Diff line
@@ -53,6 +53,9 @@ OPTIONS 
	  - 'time': Disable/enable time stamping. Acceptable values are 1 for

		    enabling time stamping. 0 for disabling time stamping.

		    The default is 1.

	  - 'call-graph': Disable/enable callgraph. Acceptable str are "fp" for

			 FP mode, "dwarf" for DWARF mode, "lbr" for LBR mode.

	  - 'stack-size': user stack size for dwarf mode

	  Note: If user explicitly sets options which conflict with the params,

	  the value set by the params will be overridden.

tools/perf/util/evsel.c

+60 −2
Original line number Diff line number Diff line
@@ -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)

tools/perf/util/evsel.h

+4 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ enum { 
	PERF_EVSEL__CONFIG_TERM_PERIOD,

	PERF_EVSEL__CONFIG_TERM_FREQ,

	PERF_EVSEL__CONFIG_TERM_TIME,

	PERF_EVSEL__CONFIG_TERM_CALLGRAPH,

	PERF_EVSEL__CONFIG_TERM_STACK_USER,

	PERF_EVSEL__CONFIG_TERM_MAX,

};
@@ -51,6 +53,8 @@ struct perf_evsel_config_term { 
		u64	period;

		u64	freq;

		bool	time;

		char	*callgraph;

		u64	stack_user;

	} val;

};

tools/perf/util/parse-events.c

+12 −0
Original line number Diff line number Diff line
@@ -614,6 +614,12 @@ do { \ 
			return -EINVAL;

		}

		break;

	case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:

		CHECK_TYPE_VAL(STR);

		break;

	case PARSE_EVENTS__TERM_TYPE_STACKSIZE:

		CHECK_TYPE_VAL(NUM);

		break;

	case PARSE_EVENTS__TERM_TYPE_NAME:

		CHECK_TYPE_VAL(STR);

		break;
@@ -668,6 +674,12 @@ do { \ 
		case PARSE_EVENTS__TERM_TYPE_TIME:

			ADD_CONFIG_TERM(TIME, time, term->val.num);

			break;

		case PARSE_EVENTS__TERM_TYPE_CALLGRAPH:

			ADD_CONFIG_TERM(CALLGRAPH, callgraph, term->val.str);

			break;

		case PARSE_EVENTS__TERM_TYPE_STACKSIZE:

			ADD_CONFIG_TERM(STACK_USER, stack_user, term->val.num);

			break;

		default:

			break;

		}

tools/perf/util/parse-events.h

+2 −0
Original line number Diff line number Diff line
@@ -65,6 +65,8 @@ enum { 
	PARSE_EVENTS__TERM_TYPE_SAMPLE_FREQ,

	PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE,

	PARSE_EVENTS__TERM_TYPE_TIME,

	PARSE_EVENTS__TERM_TYPE_CALLGRAPH,

	PARSE_EVENTS__TERM_TYPE_STACKSIZE,

};



struct parse_events_term {

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