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Subject[PATCH v1 8/8] perf docs: extend record mode docs with info on --ctl-fd[-ack] options

Extend perf-record.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 <>
tools/perf/Documentation/perf-record.txt | 37 ++++++++++++++++++++++++
1 file changed, 37 insertions(+)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 7f4db7592467..939e8eb864fe 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -587,6 +587,43 @@ Make a copy of /proc/kcore and place it into a directory with the perf data file
Limit the sample data max size, <size> is expected to be a number with
appended unit character - B/K/M/G

+Listen on ctl-fd descriptor for command to control measurement ('r': resume,
+'p': pause). Optionally send control command completion ('a') to fd-ack descriptor
+to synchronize with the controlling process. Example of bash shell script
+to resume and pause measurements:
+test -p ${ctl_fifo} && unlink ${ctl_fifo}
+mkfifo ${ctl_fifo}
+exec {ctl_fd}<>${ctl_fifo}
+test -p ${ctl_ack_fifo} && unlink ${ctl_ack_fifo}
+mkfifo ${ctl_ack_fifo}
+exec {ctl_fd_ack}<>${ctl_ack_fifo}
+perf record -D -1 -e cpu-cycles -a \
+ --ctl-fd ${ctl_fd} --ctl-fd-ack ${ctl_fd_ack} \
+ -- sleep 30 &
+sleep 5 && echo 'r' >&${ctl_fd} && read -u ${ctl_fd_ack} r1 && echo "resumed(${r1})"
+sleep 10 && echo 'p' >&${ctl_fd} && read -u ${ctl_fd_ack} p1 && echo "paused(${p1})"
+exec {ctl_fd_ack}>&-
+unlink ${ctl_ack_fifo}
+exec {ctl_fd}>&-
+unlink ${ctl_fifo}
+wait -n ${perf_pid}
+exit $?
linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1]
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