Messages in this thread | | | Subject | Re: [PATCH v4 10/10] perf record: introduce --ctl-fd[-ack] options | From | Adrian Hunter <> | Date | Wed, 3 Jun 2020 15:05:07 +0300 |
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On 25/05/20 5:23 pm, Alexey Budankov wrote: > > Introduce --ctl-fd[-ack] options to pass open file descriptors numbers > from command line. 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 | 39 ++++++++++++++++++++++++ > tools/perf/builtin-record.c | 10 ++++++ > tools/perf/util/record.h | 2 ++ > 3 files changed, 51 insertions(+) > > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt > index c2c4ce7ccee2..5c012cfe68a4 100644 > --- a/tools/perf/Documentation/perf-record.txt > +++ b/tools/perf/Documentation/perf-record.txt > @@ -614,6 +614,45 @@ appended unit character - B/K/M/G > The number of threads to run when synthesizing events for existing processes. > By default, the number of threads equals 1. > > +--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.
You should also explain the use of --delay=-1 here.
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 record -D -1 -e cpu-cycles -a \ > + --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 $? > + > + > SEE ALSO > -------- > linkperf:perf-stat[1], linkperf:perf-list[1], linkperf:perf-intel-pt[1] > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 1ff3b7a77283..e057a2be42b7 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -1761,6 +1761,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) > perf_evlist__start_workload(rec->evlist); > } > > + if (evlist__initialize_ctlfd(rec->evlist, opts->ctl_fd, opts->ctl_fd_ack)) > + goto out_child; > + > if (opts->initial_delay) { > pr_info(EVLIST_DISABLED_MSG); > if (opts->initial_delay > 0) { > @@ -1907,6 +1910,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv) > record__synthesize_workload(rec, true); > > out_child: > + evlist__finalize_ctlfd(rec->evlist); > record__mmap_read_all(rec, true); > record__aio_mmap_read_sync(rec); > > @@ -2392,6 +2396,8 @@ static struct record record = { > }, > .mmap_flush = MMAP_FLUSH_DEFAULT, > .nr_threads_synthesize = 1, > + .ctl_fd = -1, > + .ctl_fd_ack = -1, > }, > .tool = { > .sample = process_sample_event, > @@ -2587,6 +2593,10 @@ static struct option __record_options[] = { > OPT_UINTEGER(0, "num-thread-synthesize", > &record.opts.nr_threads_synthesize, > "number of threads to run for event synthesis"), > + OPT_INTEGER(0, "ctl-fd", &record.opts.ctl_fd, > + "Listen on fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events)"), > + OPT_INTEGER(0, "ctl-fd-ack", &record.opts.ctl_fd_ack, > + "Send control command completion ('ack') to fd ack descriptor"), > OPT_END() > }; > > diff --git a/tools/perf/util/record.h b/tools/perf/util/record.h > index 96a73bbd8cd4..da18aeca3623 100644 > --- a/tools/perf/util/record.h > +++ b/tools/perf/util/record.h > @@ -69,6 +69,8 @@ struct record_opts { > int mmap_flush; > unsigned int comp_level; > unsigned int nr_threads_synthesize; > + int ctl_fd; > + int ctl_fd_ack; > }; > > extern const char * const *record_usage; >
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