Commit 8dc58101 authored by Tom Zanussi's avatar Tom Zanussi Committed by Ingo Molnar
Browse files

perf: Add pipe-specific header read/write and event processing code 



This patch makes several changes to allow the perf event stream
to be sent and received over a pipe:

- adds pipe-specific versions of the header read/write code

- adds pipe-specific version of the event processing code

- adds a range of event types to be used for header or other
  pseudo events, above the range used by the kernel

- checks the return value of event handlers, which they can use
  to skip over large events during event processing rather than actually
  reading them into event objects.

- unifies the multiple do_read() functions and updates its
  users.

Note that none of these changes affect the existing perf data
file format or processing - this code only comes into play if
perf output is sent to stdout (or is read from stdin).

Signed-off-by: default avatarTom Zanussi <tzanussi@gmail.com>
Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-2-git-send-email-tzanussi@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c0555642

tools/perf/builtin-record.c

+1 −1
Original line number Diff line number Diff line
@@ -487,7 +487,7 @@ static int __cmd_record(int argc, const char **argv) 
	}



	if (!file_new) {

		err = perf_header__read(&session->header, output);

		err = perf_header__read(session, output);

		if (err < 0)

			return err;

	}

tools/perf/util/event.h

+4 −0
Original line number Diff line number Diff line
@@ -83,6 +83,10 @@ struct build_id_event { 
	char			 filename[];

};



enum perf_header_event_type { /* above any possible kernel type */

	PERF_RECORD_HEADER_MAX			= 64,

};



typedef union event_union {

	struct perf_event_header	header;

	struct ip_event			ip;

tools/perf/util/header.c

+60 −18
Original line number Diff line number Diff line
@@ -427,6 +427,25 @@ out_free: 
	return err;

}



int perf_header__write_pipe(int fd)

{

	struct perf_pipe_file_header f_header;

	int err;



	f_header = (struct perf_pipe_file_header){

		.magic	   = PERF_MAGIC,

		.size	   = sizeof(f_header),

	};



	err = do_write(fd, &f_header, sizeof(f_header));

	if (err < 0) {

		pr_debug("failed to write perf pipe header\n");

		return err;

	}



	return 0;

}



int perf_header__write(struct perf_header *self, int fd, bool at_exit)

{

	struct perf_file_header f_header;
@@ -518,25 +537,10 @@ int perf_header__write(struct perf_header *self, int fd, bool at_exit) 
	return 0;

}



static int do_read(int fd, void *buf, size_t size)

{

	while (size) {

		int ret = read(fd, buf, size);



		if (ret <= 0)

			return -1;



		size -= ret;

		buf += ret;

	}



	return 0;

}



static int perf_header__getbuffer64(struct perf_header *self,

				    int fd, void *buf, size_t size)

{

	if (do_read(fd, buf, size))

	if (do_read(fd, buf, size) <= 0)

		return -1;



	if (self->needs_swap)
@@ -592,7 +596,7 @@ int perf_file_header__read(struct perf_file_header *self, 
{

	lseek(fd, 0, SEEK_SET);



	if (do_read(fd, self, sizeof(*self)) ||

	if (do_read(fd, self, sizeof(*self)) <= 0 ||

	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))

		return -1;
@@ -662,13 +666,51 @@ static int perf_file_section__process(struct perf_file_section *self, 
	return 0;

}



int perf_header__read(struct perf_header *self, int fd)

static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,

				       struct perf_header *ph, int fd)

{

	if (do_read(fd, self, sizeof(*self)) <= 0 ||

	    memcmp(&self->magic, __perf_magic, sizeof(self->magic)))

		return -1;



	if (self->size != sizeof(*self)) {

		u64 size = bswap_64(self->size);



		if (size != sizeof(*self))

			return -1;



		ph->needs_swap = true;

	}



	return 0;

}



static int perf_header__read_pipe(struct perf_session *session, int fd)

{

	struct perf_header *self = &session->header;

	struct perf_pipe_file_header f_header;



	if (perf_file_header__read_pipe(&f_header, self, fd) < 0) {

		pr_debug("incompatible file format\n");

		return -EINVAL;

	}



	session->fd = fd;



	return 0;

}



int perf_header__read(struct perf_session *session, int fd)

{

	struct perf_header *self = &session->header;

	struct perf_file_header	f_header;

	struct perf_file_attr	f_attr;

	u64			f_id;

	int nr_attrs, nr_ids, i, j;



	if (session->fd_pipe)

		return perf_header__read_pipe(session, fd);



	if (perf_file_header__read(&f_header, self, fd) < 0) {

		pr_debug("incompatible file format\n");

		return -EINVAL;

tools/perf/util/header.h

+7 −1
Original line number Diff line number Diff line
@@ -39,6 +39,11 @@ struct perf_file_header { 
	DECLARE_BITMAP(adds_features, HEADER_FEAT_BITS);

};



struct perf_pipe_file_header {

	u64				magic;

	u64				size;

};



struct perf_header;



int perf_file_header__read(struct perf_file_header *self,
@@ -60,8 +65,9 @@ struct perf_header { 
int perf_header__init(struct perf_header *self);

void perf_header__exit(struct perf_header *self);



int perf_header__read(struct perf_header *self, int fd);

int perf_header__read(struct perf_session *session, int fd);

int perf_header__write(struct perf_header *self, int fd, bool at_exit);

int perf_header__write_pipe(int fd);



int perf_header__add_attr(struct perf_header *self,

			  struct perf_header_attr *attr);

tools/perf/util/session.c

+126 −9
Original line number Diff line number Diff line
@@ -14,6 +14,16 @@ static int perf_session__open(struct perf_session *self, bool force) 
{

	struct stat input_stat;



	if (!strcmp(self->filename, "-")) {

		self->fd_pipe = true;

		self->fd = STDIN_FILENO;



		if (perf_header__read(self, self->fd) < 0)

			pr_err("incompatible file format");



		return 0;

	}



	self->fd = open(self->filename, O_RDONLY);

	if (self->fd < 0) {

		pr_err("failed to open file: %s", self->filename);
@@ -38,7 +48,7 @@ static int perf_session__open(struct perf_session *self, bool force) 
		goto out_close;

	}



	if (perf_header__read(&self->header, self->fd) < 0) {

	if (perf_header__read(self, self->fd) < 0) {

		pr_err("incompatible file format");

		goto out_close;

	}
@@ -52,6 +62,11 @@ out_close: 
	return -1;

}



void perf_session__update_sample_type(struct perf_session *self)

{

	self->sample_type = perf_header__sample_type(&self->header);

}



struct perf_session *perf_session__new(const char *filename, int mode, bool force)

{

	size_t len = filename ? strlen(filename) + 1 : 0;
@@ -85,7 +100,7 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc 
			goto out_delete;

	}



	self->sample_type = perf_header__sample_type(&self->header);

	perf_session__update_sample_type(self);

out:

	return self;

out_free:
@@ -200,15 +215,18 @@ static const char *event__name[] = { 
	[PERF_RECORD_SAMPLE]	 = "SAMPLE",

};



unsigned long event__total[PERF_RECORD_MAX];

unsigned long event__total[PERF_RECORD_HEADER_MAX];



void event__print_totals(void)

{

	int i;

	for (i = 0; i < PERF_RECORD_MAX; ++i)

	for (i = 0; i < PERF_RECORD_HEADER_MAX; ++i) {

		if (!event__name[i])

			continue;

		pr_info("%10s events: %10ld\n",

			event__name[i], event__total[i]);

	}

}



void mem_bswap_64(void *src, int byte_size)

{
@@ -271,7 +289,7 @@ static event__swap_op event__swap_ops[] = { 
	[PERF_RECORD_LOST]   = event__all64_swap,

	[PERF_RECORD_READ]   = event__read_swap,

	[PERF_RECORD_SAMPLE] = event__all64_swap,

	[PERF_RECORD_MAX]    = NULL,

	[PERF_RECORD_HEADER_MAX]    = NULL,

};



static int perf_session__process_event(struct perf_session *self,
@@ -281,7 +299,7 @@ static int perf_session__process_event(struct perf_session *self, 
{

	trace_event(event);



	if (event->header.type < PERF_RECORD_MAX) {

	if (event->header.type < PERF_RECORD_HEADER_MAX) {

		dump_printf("%#Lx [%#x]: PERF_RECORD_%s",

			    offset + head, event->header.size,

			    event__name[event->header.type]);
@@ -376,6 +394,101 @@ static struct thread *perf_session__register_idle_thread(struct perf_session *se 
	return thread;

}



int do_read(int fd, void *buf, size_t size)

{

	void *buf_start = buf;



	while (size) {

		int ret = read(fd, buf, size);



		if (ret <= 0)

			return ret;



		size -= ret;

		buf += ret;

	}



	return buf - buf_start;

}



#define session_done()	(*(volatile int *)(&session_done))

volatile int session_done;



static int __perf_session__process_pipe_events(struct perf_session *self,

					       struct perf_event_ops *ops)

{

	event_t event;

	uint32_t size;

	int skip = 0;

	u64 head;

	int err;

	void *p;



	perf_event_ops__fill_defaults(ops);



	head = 0;

more:

	err = do_read(self->fd, &event, sizeof(struct perf_event_header));

	if (err <= 0) {

		if (err == 0)

			goto done;



		pr_err("failed to read event header\n");

		goto out_err;

	}



	if (self->header.needs_swap)

		perf_event_header__bswap(&event.header);



	size = event.header.size;

	if (size == 0)

		size = 8;



	p = &event;

	p += sizeof(struct perf_event_header);



	err = do_read(self->fd, p, size - sizeof(struct perf_event_header));

	if (err <= 0) {

		if (err == 0) {

			pr_err("unexpected end of event stream\n");

			goto done;

		}



		pr_err("failed to read event data\n");

		goto out_err;

	}



	if (size == 0 ||

	    (skip = perf_session__process_event(self, &event, ops,

						0, head)) < 0) {

		dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",

			    head, event.header.size, event.header.type);

		/*

		 * assume we lost track of the stream, check alignment, and

		 * increment a single u64 in the hope to catch on again 'soon'.

		 */

		if (unlikely(head & 7))

			head &= ~7ULL;



		size = 8;

	}



	head += size;



	dump_printf("\n%#Lx [%#x]: event: %d\n",

		    head, event.header.size, event.header.type);



	if (skip > 0)

		head += skip;



	if (!session_done())

		goto more;

done:

	err = 0;

out_err:

	return err;

}



int __perf_session__process_events(struct perf_session *self,

				   u64 data_offset, u64 data_size,

				   u64 file_size, struct perf_event_ops *ops)
@@ -499,9 +612,13 @@ out_getcwd_err: 
		self->cwdlen = strlen(self->cwd);

	}



	err = __perf_session__process_events(self, self->header.data_offset,

	if (!self->fd_pipe)

		err = __perf_session__process_events(self,

						     self->header.data_offset,

						     self->header.data_size,

						     self->size, ops);

	else

		err = __perf_session__process_pipe_events(self, ops);

out_err:

	return err;

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE