lkml.org 
[lkml]   [2020]   [Jun]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH v4 10/10] perf record: introduce --ctl-fd[-ack] options
    From
    Date
    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;
    >

    \
     
     \ /
      Last update: 2020-06-03 14:09    [W:4.120 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site