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Commit 77170988 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

perf trace: Don't relookup fields by name in each sample 

Instead do the lookups just when creating the tracepoints, initially for
the most common, raw_syscalls:sys_{enter,exit}.

It works by having evsel->priv have a per tracepoint structure with
entries for the fields, for direct access, with the offset and a
function to get the value from the sample, doing the swap if needed.

Using a simple workload that does M millions write syscalls, we go from:

 # perf stat -i -e cycles /tmp/oldperf trace ./sc_hello 100 > /dev/null

 Performance counter stats for '/tmp/oldperf trace ./sc_hello 100':

     8,366,771,459 cycles

       2.668025928 seconds time elapsed

 # perf stat -i -e cycles perf trace ./sc_hello 100 > /dev/null

 Performance counter stats for 'perf trace ./sc_hello 100':

     8,345,187,650 cycles

       2.631748425 seconds time elapsed

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-eyfhvoo510a5i10b27dnvm88@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a614d01b

tools/perf/builtin-trace.c

+188 −11
Original line number Diff line number Diff line
@@ -35,6 +35,189 @@ 
# define MADV_UNMERGEABLE	13

#endif



struct tp_field {

	int offset;

	union {

		u64 (*integer)(struct tp_field *field, struct perf_sample *sample);

		void *(*pointer)(struct tp_field *field, struct perf_sample *sample);

	};

};



#define TP_UINT_FIELD(bits) \

static u64 tp_field__u##bits(struct tp_field *field, struct perf_sample *sample) \

{ \

	return *(u##bits *)(sample->raw_data + field->offset); \

}



TP_UINT_FIELD(8);

TP_UINT_FIELD(16);

TP_UINT_FIELD(32);

TP_UINT_FIELD(64);



#define TP_UINT_FIELD__SWAPPED(bits) \

static u64 tp_field__swapped_u##bits(struct tp_field *field, struct perf_sample *sample) \

{ \

	u##bits value = *(u##bits *)(sample->raw_data + field->offset); \

	return bswap_##bits(value);\

}



TP_UINT_FIELD__SWAPPED(16);

TP_UINT_FIELD__SWAPPED(32);

TP_UINT_FIELD__SWAPPED(64);



static int tp_field__init_uint(struct tp_field *field,

			       struct format_field *format_field,

			       bool needs_swap)

{

	field->offset = format_field->offset;



	switch (format_field->size) {

	case 1:

		field->integer = tp_field__u8;

		break;

	case 2:

		field->integer = needs_swap ? tp_field__swapped_u16 : tp_field__u16;

		break;

	case 4:

		field->integer = needs_swap ? tp_field__swapped_u32 : tp_field__u32;

		break;

	case 8:

		field->integer = needs_swap ? tp_field__swapped_u64 : tp_field__u64;

		break;

	default:

		return -1;

	}



	return 0;

}



static void *tp_field__ptr(struct tp_field *field, struct perf_sample *sample)

{

	return sample->raw_data + field->offset;

}



static int tp_field__init_ptr(struct tp_field *field, struct format_field *format_field)

{

	field->offset = format_field->offset;

	field->pointer = tp_field__ptr;

	return 0;

}



struct syscall_tp {

	struct tp_field id;

	union {

		struct tp_field args, ret;

	};

};



static int perf_evsel__init_tp_uint_field(struct perf_evsel *evsel,

					  struct tp_field *field,

					  const char *name)

{

	struct format_field *format_field = perf_evsel__field(evsel, name);



	if (format_field == NULL)

		return -1;



	return tp_field__init_uint(field, format_field, evsel->needs_swap);

}



#define perf_evsel__init_sc_tp_uint_field(evsel, name) \

	({ struct syscall_tp *sc = evsel->priv;\

	   perf_evsel__init_tp_uint_field(evsel, &sc->name, #name); })



static int perf_evsel__init_tp_ptr_field(struct perf_evsel *evsel,

					 struct tp_field *field,

					 const char *name)

{

	struct format_field *format_field = perf_evsel__field(evsel, name);



	if (format_field == NULL)

		return -1;



	return tp_field__init_ptr(field, format_field);

}



#define perf_evsel__init_sc_tp_ptr_field(evsel, name) \

	({ struct syscall_tp *sc = evsel->priv;\

	   perf_evsel__init_tp_ptr_field(evsel, &sc->name, #name); })



static void perf_evsel__delete_priv(struct perf_evsel *evsel)

{

	free(evsel->priv);

	evsel->priv = NULL;

	perf_evsel__delete(evsel);

}



static struct perf_evsel *perf_evsel__syscall_newtp(const char *direction,

						    void *handler, int idx)

{

	struct perf_evsel *evsel = perf_evsel__newtp("raw_syscalls", direction, idx);



	if (evsel) {

		evsel->priv = malloc(sizeof(struct syscall_tp));



		if (evsel->priv == NULL)

			goto out_delete;



		if (perf_evsel__init_sc_tp_uint_field(evsel, id))

			goto out_delete;



		evsel->handler = handler;

	}



	return evsel;



out_delete:

	perf_evsel__delete_priv(evsel);

	return NULL;

}



#define perf_evsel__sc_tp_uint(evsel, name, sample) \

	({ struct syscall_tp *fields = evsel->priv; \

	   fields->name.integer(&fields->name, sample); })



#define perf_evsel__sc_tp_ptr(evsel, name, sample) \

	({ struct syscall_tp *fields = evsel->priv; \

	   fields->name.pointer(&fields->name, sample); })



static int perf_evlist__add_syscall_newtp(struct perf_evlist *evlist,

					  void *sys_enter_handler,

					  void *sys_exit_handler)

{

	int ret = -1;

	int idx = evlist->nr_entries;

	struct perf_evsel *sys_enter, *sys_exit;



	sys_enter = perf_evsel__syscall_newtp("sys_enter", sys_enter_handler, idx++);

	if (sys_enter == NULL)

		goto out;



	if (perf_evsel__init_sc_tp_ptr_field(sys_enter, args))

		goto out_delete_sys_enter;



	sys_exit = perf_evsel__syscall_newtp("sys_exit", sys_exit_handler, idx++);

	if (sys_exit == NULL)

		goto out_delete_sys_enter;



	if (perf_evsel__init_sc_tp_uint_field(sys_exit, ret))

		goto out_delete_sys_exit;



	perf_evlist__add(evlist, sys_enter);

	perf_evlist__add(evlist, sys_exit);



	ret = 0;

out:

	return ret;



out_delete_sys_exit:

	perf_evsel__delete_priv(sys_exit);

out_delete_sys_enter:

	perf_evsel__delete_priv(sys_enter);

	goto out;

}





struct syscall_arg {

	unsigned long val;

	struct thread *thread;
@@ -1392,7 +1575,7 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel, 
	void *args;

	size_t printed = 0;

	struct thread *thread;

	int id = perf_evsel__intval(evsel, sample, "id");

	int id = perf_evsel__sc_tp_uint(evsel, id, sample);

	struct syscall *sc = trace__syscall_info(trace, evsel, id);

	struct thread_trace *ttrace;
@@ -1407,12 +1590,7 @@ static int trace__sys_enter(struct trace *trace, struct perf_evsel *evsel, 
	if (ttrace == NULL)

		return -1;



	args = perf_evsel__rawptr(evsel, sample, "args");

	if (args == NULL) {

		fprintf(trace->output, "Problems reading syscall arguments\n");

		return -1;

	}



	args = perf_evsel__sc_tp_ptr(evsel, args, sample);

	ttrace = thread->priv;



	if (ttrace->entry_str == NULL) {
@@ -1445,7 +1623,7 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel, 
	int ret;

	u64 duration = 0;

	struct thread *thread;

	int id = perf_evsel__intval(evsel, sample, "id");

	int id = perf_evsel__sc_tp_uint(evsel, id, sample);

	struct syscall *sc = trace__syscall_info(trace, evsel, id);

	struct thread_trace *ttrace;
@@ -1463,7 +1641,7 @@ static int trace__sys_exit(struct trace *trace, struct perf_evsel *evsel, 
	if (trace->summary)

		thread__update_stats(ttrace, id, sample);



	ret = perf_evsel__intval(evsel, sample, "ret");

	ret = perf_evsel__sc_tp_uint(evsel, ret, sample);



	if (id == trace->audit.open_id && ret >= 0 && trace->last_vfs_getname) {

		trace__set_fd_pathname(thread, ret, trace->last_vfs_getname);
@@ -1675,8 +1853,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv) 
		goto out;

	}



	if (perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_enter", trace__sys_enter) ||

		perf_evlist__add_newtp(evlist, "raw_syscalls", "sys_exit", trace__sys_exit))

	if (perf_evlist__add_syscall_newtp(evlist, trace__sys_enter, trace__sys_exit))

		goto out_error_tp;



	perf_evlist__add_vfs_getname(evlist);