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Commit dc323ce8 authored by Stephane Eranian's avatar Stephane Eranian Committed by Arnaldo Carvalho de Melo
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perf script: Enable printing of branch stack 



This patch improves perf script by enabling printing of the
branch stack via the 'brstack' and 'brstacksym' arguments to
the field selection option -F. The option is off by default
and operates only if the perf.data file has branch stack content.

The branches are printed in to/from pairs. The most recent branch
is printed first. The number of branch entries vary based on the
underlying hardware and filtering used.

The brstack prints FROM/TO addresses in raw hexadecimal format.
The brstacksym prints FROM/TO addresses in symbolic form wherever
possible.

 $ perf script -F ip,brstack
  5d3000 0x401aa0/0x5d2000/M/-/-/-/0 ...

 $ perf script -F ip,brstacksym
  4011e0 noploop+0x0/noploop+0x0/P/-/-/0

The notation F/T/M/X/A/C describes the attributes of the branch.
F=from, T=to, M/P=misprediction/prediction, X=TSX, A=TSX abort, C=cycles (SKL)

Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yuanfang Chen <cyfmxc@gmail.com>
Link: http://lkml.kernel.org/r/1441039273-16260-5-git-send-email-eranian@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 729a7841

tools/perf/Documentation/perf-script.txt

+12 −2
Original line number Diff line number Diff line
@@ -112,11 +112,11 @@ OPTIONS 
--debug-mode::

        Do various checks like samples ordering and lost events.



-f::

-F::

--fields::

        Comma separated list of fields to print. Options are:

        comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,

	srcline, period, iregs, flags.

	srcline, period, iregs, brstack, brstacksym, flags.

        Field list can be prepended with the type, trace, sw or hw,

        to indicate to which event type the field list applies.

        e.g., -f sw:comm,tid,time,ip,sym  and -f trace:time,cpu,trace
@@ -175,6 +175,16 @@ OPTIONS 
	Finally, a user may not set fields to none for all event types.

	i.e., -f "" is not allowed.



	The brstack output includes branch related information with raw addresses using the

	/v/v/v/v/ syntax in the following order:

	FROM: branch source instruction

	TO  : branch target instruction

        M/P/-: M=branch target mispredicted or branch direction was mispredicted, P=target predicted or direction predicted, -=not supported

	X/- : X=branch inside a transactional region, -=not in transaction region or not supported

	A/- : A=TSX abort entry, -=not aborted region or not supported



	The brstacksym is identical to brstack, except that the FROM and TO addresses are printed in a symbolic form if possible.



-k::

--vmlinux=<file>::

        vmlinux pathname

tools/perf/builtin-script.c

+81 −1
Original line number Diff line number Diff line
@@ -51,6 +51,8 @@ enum perf_output_field { 
	PERF_OUTPUT_SRCLINE         = 1U << 12,

	PERF_OUTPUT_PERIOD          = 1U << 13,

	PERF_OUTPUT_IREGS	    = 1U << 14,

	PERF_OUTPUT_BRSTACK	    = 1U << 15,

	PERF_OUTPUT_BRSTACKSYM	    = 1U << 16,

};



struct output_option {
@@ -72,6 +74,8 @@ struct output_option { 
	{.str = "srcline", .field = PERF_OUTPUT_SRCLINE},

	{.str = "period", .field = PERF_OUTPUT_PERIOD},

	{.str = "iregs", .field = PERF_OUTPUT_IREGS},

	{.str = "brstack", .field = PERF_OUTPUT_BRSTACK},

	{.str = "brstacksym", .field = PERF_OUTPUT_BRSTACKSYM},

};



/* default set to maintain compatibility with current format */
@@ -425,6 +429,77 @@ static void print_sample_start(struct perf_sample *sample, 
	}

}



static inline char

mispred_str(struct branch_entry *br)

{

	if (!(br->flags.mispred  || br->flags.predicted))

		return '-';



	return br->flags.predicted ? 'P' : 'M';

}



static void print_sample_brstack(union perf_event *event __maybe_unused,

			  struct perf_sample *sample,

			  struct thread *thread __maybe_unused,

			  struct perf_event_attr *attr __maybe_unused)

{

	struct branch_stack *br = sample->branch_stack;

	u64 i;



	if (!(br && br->nr))

		return;



	for (i = 0; i < br->nr; i++) {

		printf(" 0x%"PRIx64"/0x%"PRIx64"/%c/%c/%c/%d ",

			br->entries[i].from,

			br->entries[i].to,

			mispred_str( br->entries + i),

			br->entries[i].flags.in_tx? 'X' : '-',

			br->entries[i].flags.abort? 'A' : '-',

			br->entries[i].flags.cycles);

	}

}



static void print_sample_brstacksym(union perf_event *event __maybe_unused,

			  struct perf_sample *sample,

			  struct thread *thread __maybe_unused,

			  struct perf_event_attr *attr __maybe_unused)

{

	struct branch_stack *br = sample->branch_stack;

	struct addr_location alf, alt;

	u8 cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;

	u64 i, from, to;



	if (!(br && br->nr))

		return;



	for (i = 0; i < br->nr; i++) {



		memset(&alf, 0, sizeof(alf));

		memset(&alt, 0, sizeof(alt));

		from = br->entries[i].from;

		to   = br->entries[i].to;



		thread__find_addr_map(thread, cpumode, MAP__FUNCTION, from, &alf);

		if (alf.map)

			alf.sym = map__find_symbol(alf.map, alf.addr, NULL);



		thread__find_addr_map(thread, cpumode, MAP__FUNCTION, to, &alt);

		if (alt.map)

			alt.sym = map__find_symbol(alt.map, alt.addr, NULL);



		symbol__fprintf_symname_offs(alf.sym, &alf, stdout);

		putchar('/');

		symbol__fprintf_symname_offs(alt.sym, &alt, stdout);

		printf("/%c/%c/%c/%d ",

			mispred_str( br->entries + i),

			br->entries[i].flags.in_tx? 'X' : '-',

			br->entries[i].flags.abort? 'A' : '-',

			br->entries[i].flags.cycles);

	}

}





static void print_sample_addr(union perf_event *event,

			  struct perf_sample *sample,

			  struct thread *thread,
@@ -560,6 +635,11 @@ static void process_event(union perf_event *event, struct perf_sample *sample, 
	if (PRINT_FIELD(IREGS))

		print_sample_iregs(event, sample, thread, attr);



	if (PRINT_FIELD(BRSTACK))

		print_sample_brstack(event, sample, thread, attr);

	else if (PRINT_FIELD(BRSTACKSYM))

		print_sample_brstacksym(event, sample, thread, attr);



	printf("\n");

}
@@ -1681,7 +1761,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused) 
		     "comma separated output fields prepend with 'type:'. "

		     "Valid types: hw,sw,trace,raw. "

		     "Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,"

		     "addr,symoff,period,iregs,flags", parse_output_fields),

		     "addr,symoff,period,iregs,brstack,brstacksym,flags", parse_output_fields),

	OPT_BOOLEAN('a', "all-cpus", &system_wide,

		    "system-wide collection from all CPUs"),

	OPT_STRING('S', "symbols", &symbol_conf.sym_list_str, "symbol[,symbol...]",