Introduce --ctl-fd[-ack] options to pass open file descriptors numbers
from command line. Extend perf-stat.txt file with --ctl-fd[-ack] options
description. Document possible usage model introduced by --ctl-fd[-ack]
options by providing example bash shell script.
Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
---
tools/perf/Documentation/perf-stat.txt | 40 ++++++++++++++++++++++++++
tools/perf/builtin-stat.c | 11 +++++++
tools/perf/util/stat.h | 2 ++
3 files changed, 53 insertions(+)
diff --git a/tools/perf/Documentation/perf-stat.txt
b/tools/perf/Documentation/perf-stat.txt
index b4d2434584f5..4b15373af800 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -164,6 +164,46 @@ with it. --append may be used here. Examples:
3>results perf stat --log-fd 3 -- $cmd
3>>results perf stat --log-fd 3 --append -- $cmd
+--ctl-fd::
+--ctl-fd-ack::
+
+Listen on ctl-fd descriptor for command to control measurement ('enable':
enable events,
+'disable': disable events). Optionally send control command completion ('ack')
to fd-ack
+descriptor to synchronize with the controlling process. Example of bash shell
script
+to enable and disable events during measurements:
+
+#!/bin/bash
+
+ctl_dir=/tmp/
+
+ctl_fifo=${ctl_dir}perf_ctl.fifo
+test -p ${ctl_fifo} && unlink ${ctl_fifo}
+mkfifo ${ctl_fifo}
+exec {ctl_fd}<>${ctl_fifo}
+
+ctl_ack_fifo=${ctl_dir}perf_ctl_ack.fifo
+test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
+mkfifo ${ctl_ack_fifo}
+exec {ctl_fd_ack}<>${ctl_ack_fifo}
+
+perf stat -D -1 -e cpu-cycles -a -I 1000 \
+ --ctl-fd ${ctl_fd} --ctl-fd-ack ${ctl_fd_ack} \
+ -- sleep 30 &
+perf_pid=$!
+
+sleep 5 && echo 'enable' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo
"enabled(${e1})"
+sleep 10 && echo 'disable' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo
"disabled(${d1})"
+
+exec {ctl_fd_ack}>&-
+unlink ${ctl_ack_fifo}
+
+exec {ctl_fd}>&-
+unlink ${ctl_fifo}
+
+wait -n ${perf_pid}
+exit $?
+
+
--pre::
--post::
Pre and post measurement hooks, e.g.:
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index c06c2b701a15..69b0e4f498c6 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -187,6 +187,8 @@ static struct perf_stat_config stat_config = {
.metric_only_len = METRIC_ONLY_LEN,
.walltime_nsecs_stats = &walltime_nsecs_stats,
.big_num = true,
+ .ctl_fd = -1,
+ .ctl_fd_ack = -1
};
static inline void diff_timespec(struct timespec *r, struct timespec *a,
@@ -1065,6 +1067,10 @@ static struct option stat_options[] = {
"Use with 'percore' event qualifier to show the event "
"counts of one hardware thread by sum up total hardware "
"threads of same physical core"),
+ OPT_INTEGER(0, "ctl-fd", &stat_config.ctl_fd,
+ "Listen on fd descriptor for command to control measurement
('enable': enable events, 'disable': disable events)"),
+ OPT_INTEGER(0, "ctl-fd-ack", &stat_config.ctl_fd_ack,
+ "Send control command completion ('ack') to fd ack
descriptor"),
OPT_END()
};
@@ -2232,6 +2238,9 @@ int cmd_stat(int argc, const char **argv)
signal(SIGALRM, skip_signal);
signal(SIGABRT, skip_signal);
+ if (evlist__initialize_ctlfd(evsel_list, stat_config.ctl_fd,
stat_config.ctl_fd_ack))
+ goto out;
+
status = 0;
for (run_idx = 0; forever || run_idx < stat_config.run_count;
run_idx++) {
if (stat_config.run_count != 1 && verbose > 0)
@@ -2251,6 +2260,8 @@ int cmd_stat(int argc, const char **argv)
if (!forever && status != -1 && (!interval || stat_config.summary))
print_counters(NULL, argc, argv);
+ evlist__finalize_ctlfd(evsel_list);
+
if (STAT_RECORD) {
/*
* We synthesize the kernel mmap record just so that older tools
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index b00d64f0ca26..65f42a04d9ef 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -131,6 +131,8 @@ struct perf_stat_config {
struct perf_cpu_map *cpus_aggr_map;
u64 *walltime_run;
struct rblist metric_events;
+ int ctl_fd;
+ int ctl_fd_ack;
};
void update_stats(struct stats *stats, u64 val);
--
2.24.1
