提交 8dc58101 编写于 作者: T Tom Zanussi 提交者: Ingo Molnar

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: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas 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: NIngo Molnar <mingo@elte.hu>
上级 c0555642
......@@ -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;
}
......
......@@ -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;
......
......@@ -427,6 +427,25 @@ static int perf_header__adds_write(struct perf_header *self, int fd)
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;
......
......@@ -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);
......
......@@ -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 @@ static int perf_session__open(struct perf_session *self, bool force)
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:
......@@ -200,14 +215,17 @@ 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 @@ int perf_session__process_events(struct perf_session *self,
self->cwdlen = strlen(self->cwd);
}
err = __perf_session__process_events(self, self->header.data_offset,
self->header.data_size,
self->size, ops);
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;
}
......
......@@ -27,6 +27,7 @@ struct perf_session {
u64 sample_type;
struct ref_reloc_sym ref_reloc_sym;
int fd;
bool fd_pipe;
int cwdlen;
char *cwd;
char filename[0];
......@@ -92,6 +93,9 @@ static inline struct map *
return map_groups__new_module(&self->kmaps, start, filename);
}
int do_read(int fd, void *buf, size_t size);
void perf_session__update_sample_type(struct perf_session *self);
#ifdef NO_NEWT_SUPPORT
static inline int perf_session__browse_hists(struct rb_root *hists __used,
u64 nr_hists __used,
......
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