Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Wed, 6 May 2020 17:27:19 -0300 | Subject | Re: [PATCH v2 11/11] perf docs: extend record mode docs with info on --ctl-fd[-ack] options |
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Em Wed, May 06, 2020 at 09:30:50PM +0300, Alexey Budankov escreveu: > > 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.
Ditto, combine this patch with the one that introduces these options.
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> > --- > tools/perf/Documentation/perf-record.txt | 39 ++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt > index 561ef55743e2..eabb00ed2f5d 100644 > --- a/tools/perf/Documentation/perf-record.txt > +++ b/tools/perf/Documentation/perf-record.txt > @@ -613,6 +613,45 @@ 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 ('e': enable events, > +'d': disable events. Optionally send control command completion ('a') 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 record -D -1 -e cpu-cycles -a \ > + --ctl-fd ${ctl_fd} --ctl-fd-ack ${ctl_fd_ack} \ > + -- sleep 30 & > +perf_pid=$! > + > +sleep 5 && echo 'e' >&${ctl_fd} && read -u ${ctl_fd_ack} e1 && echo "resumed(${e1})" > +sleep 10 && echo 'd' >&${ctl_fd} && read -u ${ctl_fd_ack} d1 && echo "paused(${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] > -- > 2.24.1 > >
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- Arnaldo
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