Messages in this thread Patch in this message | | | Subject | [PATCH v1 8/8] perf docs: extend record mode docs with info on --ctl-fd[-ack] options | From | Alexey Budankov <> | Date | Fri, 27 Mar 2020 11:51:08 +0300 |
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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 <alexey.budankov@linux.intel.com> --- 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 +--ctl-fd:: +--ctl-fd-ack:: +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: +#!/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 record -D -1 -e cpu-cycles -a \ + --ctl-fd ${ctl_fd} --ctl-fd-ack ${ctl_fd_ack} \ + -- sleep 30 & +perf_pid=$! + +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 $? + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1] -- 2.24.1
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