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/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 44889c9..43f19c1 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -51,6 +51,7 @@
static unsigned long page_size;
static ssize_t calc_data_size;
+static bool repipe;
static int do_read(int fd, void *buf, int size)
{
@@ -62,6 +63,13 @@
if (ret <= 0)
return -1;
+ if (repipe) {
+ int retw = write(STDOUT_FILENO, buf, ret);
+
+ if (retw <= 0 || retw != ret)
+ die("repiping input file");
+ }
+
size -= ret;
buf += ret;
}
@@ -116,6 +124,13 @@
if (!r)
die("no data");
+ if (repipe) {
+ int retw = write(STDOUT_FILENO, &c, 1);
+
+ if (retw <= 0 || retw != r)
+ die("repiping input file string");
+ }
+
buf[size++] = c;
if (!c)
@@ -454,7 +469,7 @@
return data;
}
-ssize_t trace_report(int fd)
+ssize_t trace_report(int fd, bool __repipe)
{
char buf[BUFSIZ];
char test[] = { 23, 8, 68 };
@@ -465,6 +480,7 @@
ssize_t size;
calc_data_size = 1;
+ repipe = __repipe;
input_fd = fd;
@@ -499,6 +515,7 @@
size = calc_data_size - 1;
calc_data_size = 0;
+ repipe = false;
if (show_funcs) {
print_funcs();