On 20.05.2020 15:38, Jiri Olsa wrote: > On Wed, May 13, 2020 at 11:03:03AM +0300, Alexey Budankov wrote: >> >> Introduce --ctl-fd[-ack] options to pass open file descriptors numbers >> from command line. Extend perf-stat.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 <[email protected]> >> --- >> tools/perf/Documentation/perf-stat.txt | 40 ++++++++++++++++++++++++++ >> tools/perf/builtin-stat.c | 10 +++++++ >> tools/perf/util/stat.h | 2 ++ >> 3 files changed, 52 insertions(+) >> >> diff --git a/tools/perf/Documentation/perf-stat.txt >> b/tools/perf/Documentation/perf-stat.txt >> index 3b91b30d7672..7f7a0019fbfc 100644 >> --- a/tools/perf/Documentation/perf-stat.txt >> +++ b/tools/perf/Documentation/perf-stat.txt >> @@ -164,6 +164,46 @@ with it. --append may be used here. Examples: >> 3>results perf stat --log-fd 3 -- $cmd >> 3>>results perf stat --log-fd 3 --append -- $cmd >> >> +--ctl-fd:: >> +--ctl-fd-ack:: >> + >> +Listen on ctl-fd descriptor for command to control measurement ('enable': >> enable events, >> +'disable': disable events). Optionally send control command completion >> ('ack') to fd-ack >> +descriptor to synchronize with the controlling process. Example of bash >> shell script >> +to enable and disable events during measurements: >> + >> +#!/bin/bash >> + >> +ctl_dir=/tmp/ >> + >> +ctl_fifo=${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 stat -D -1 -e cpu-cycles -a -I 1000 \ >> + --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 $? >> + >> + >> --pre:: >> --post:: >> Pre and post measurement hooks, e.g.: >> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c >> index abea82a1ba24..88055aaf670f 100644 >> --- a/tools/perf/builtin-stat.c >> +++ b/tools/perf/builtin-stat.c >> @@ -187,6 +187,8 @@ static struct perf_stat_config stat_config = { >> .metric_only_len = METRIC_ONLY_LEN, >> .walltime_nsecs_stats = &walltime_nsecs_stats, >> .big_num = true, >> + .ctl_fd = -1, >> + .ctl_fd_ack = -1 >> }; >> >> static inline void diff_timespec(struct timespec *r, struct timespec *a, >> @@ -984,6 +986,10 @@ static struct option stat_options[] = { >> "Use with 'percore' event qualifier to show the event " >> "counts of one hardware thread by sum up total hardware " >> "threads of same physical core"), >> + OPT_INTEGER(0, "ctl-fd", &stat_config.ctl_fd, >> + "Listen on fd descriptor for command to control measurement >> ('enable': enable events, 'disable': disable events)"), >> + OPT_INTEGER(0, "ctl-fd-ack", &stat_config.ctl_fd_ack, >> + "Send control command completion ('ack') to fd ack >> descriptor"), >> OPT_END() >> }; >> >> @@ -2180,6 +2186,8 @@ int cmd_stat(int argc, const char **argv) >> signal(SIGALRM, skip_signal); >> signal(SIGABRT, skip_signal); >> >> + evlist__initialize_ctlfd(evsel_list, stat_config.ctl_fd, >> stat_config.ctl_fd_ack); > > please check the return value
Accepted in v4. ~Alexey
