perf: add perf-inject builtin
Currently, perf 'live mode' writes build-ids at the end of the
session, which isn't actually useful for processing live mode events.
What would be better would be to have the build-ids sent before any of
the samples that reference them, which can be done by processing the
event stream and retrieving the build-ids on the first hit. Doing
that in perf-record itself, however, is off-limits.
This patch introduces perf-inject, which does the same job while
leaving perf-record untouched. Normal mode perf still records the
build-ids at the end of the session as it should, but for live mode,
perf-inject can be injected in between the record and report steps
e.g.:
perf record -o - ./hackbench 10 | perf inject -v -b | perf report -v -i -
perf-inject reads a perf-record event stream and repipes it to stdout.
At any point the processing code can inject other events into the
event stream - in this case build-ids (-b option) are read and
injected as needed into the event stream.
Build-ids are just the first user of perf-inject - potentially
anything that needs userspace processing to augment the trace stream
with additional information could make use of this facility.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1272696080-16435-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2d1d97e..79da0e5 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -713,10 +713,18 @@
dso = __dsos__findnew(head, filename);
if (dso != NULL) {
+ char sbuild_id[BUILD_ID_SIZE * 2 + 1];
+
dso__set_build_id(dso, &bev->build_id);
- if (filename[0] == '[')
- dso->kernel = dso_type;
- }
+
+ if (filename[0] == '[')
+ dso->kernel = dso_type;
+
+ build_id__sprintf(dso->build_id, sizeof(dso->build_id),
+ sbuild_id);
+ pr_debug("build id event received for %s: %s\n",
+ dso->long_name, sbuild_id);
+ }
err = 0;
out:
@@ -767,7 +775,7 @@
switch (feat) {
case HEADER_TRACE_INFO:
- trace_report(fd);
+ trace_report(fd, false);
break;
case HEADER_BUILD_ID:
@@ -782,12 +790,16 @@
}
static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
- struct perf_header *ph, int fd)
+ struct perf_header *ph, int fd,
+ bool repipe)
{
if (do_read(fd, self, sizeof(*self)) <= 0 ||
memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
return -1;
+ if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
+ return -1;
+
if (self->size != sizeof(*self)) {
u64 size = bswap_64(self->size);
@@ -805,7 +817,8 @@
struct perf_header *self = &session->header;
struct perf_pipe_file_header f_header;
- if (perf_file_header__read_pipe(&f_header, self, fd) < 0) {
+ if (perf_file_header__read_pipe(&f_header, self, fd,
+ session->repipe) < 0) {
pr_debug("incompatible file format\n");
return -EINVAL;
}
@@ -1096,12 +1109,17 @@
lseek(session->fd, offset + sizeof(struct tracing_data_event),
SEEK_SET);
- size_read = trace_report(session->fd);
+ size_read = trace_report(session->fd, session->repipe);
padding = ALIGN(size_read, sizeof(u64)) - size_read;
if (read(session->fd, buf, padding) < 0)
die("reading input file");
+ if (session->repipe) {
+ int retw = write(STDOUT_FILENO, buf, padding);
+ if (retw <= 0 || retw != padding)
+ die("repiping tracing data padding");
+ }
if (size_read + padding != size)
die("tracing data size mismatch");
@@ -1110,7 +1128,8 @@
}
int event__synthesize_build_id(struct dso *pos, u16 misc,
- event__handler_t process, struct machine *machine,
+ event__handler_t process,
+ struct machine *machine,
struct perf_session *session)
{
event_t ev;