From 27e9769aad3c435993a2e0cd91f5d868294145d0 Mon Sep 17 00:00:00 2001 From: Alexey Budankov Date: Fri, 17 Jul 2020 10:05:41 +0300 Subject: [PATCH] perf stat: Introduce --control fd:ctl-fd[,ack-fd] options Introduce --control fd:ctl-fd[,ack-fd] options to pass open file descriptors numbers from command line. Extend perf-stat.txt file with --control fd:ctl-fd[,ack-fd] options description. Document possible usage model introduced by --control fd:ctl-fd[,ack-fd] options by providing example bash shell script. Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/feabd5cf-0155-fb0a-4587-c71571f2d517@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-stat.txt | 39 +++++++++++++++++++++++++++++++++ tools/perf/builtin-stat.c | 40 +++++++++++++++++++++++++++++++++- tools/perf/util/stat.h | 2 ++ 3 files changed, 80 insertions(+), 1 deletion(-) diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 9f32f6c..c9bfefc 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -176,6 +176,45 @@ with it. --append may be used here. Examples: 3>results perf stat --log-fd 3 -- $cmd 3>>results perf stat --log-fd 3 --append -- $cmd +--control fd:ctl-fd[,ack-fd] +Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, +'disable': disable events). Measurements can be started with events disabled using +--delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor +to synchronize with the controlling process. Example of bash shell script to enable and +disable events during measurements: + +#!/bin/bash + +ctl_dir=/tmp/ + +ctl_fifo=${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 \ + --control fd:${ctl_fd},${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 5280a45..483a28e 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -188,6 +188,8 @@ 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 bool cpus_map_matched(struct evsel *a, struct evsel *b) @@ -867,7 +869,7 @@ try_again_reset: perf_evlist__start_workload(evsel_list); enable_counters(); - if (interval || timeout) + if (interval || timeout || evlist__ctlfd_initialized(evsel_list)) status = dispatch_events(forks, timeout, interval, ×); if (child_pid != -1) { if (timeout) @@ -1039,6 +1041,33 @@ static int parse_metric_groups(const struct option *opt, &stat_config.metric_events); } +static int parse_control_option(const struct option *opt, + const char *str, + int unset __maybe_unused) +{ + char *comma = NULL, *endptr = NULL; + struct perf_stat_config *config = (struct perf_stat_config *)opt->value; + + if (strncmp(str, "fd:", 3)) + return -EINVAL; + + config->ctl_fd = strtoul(&str[3], &endptr, 0); + if (endptr == &str[3]) + return -EINVAL; + + comma = strchr(str, ','); + if (comma) { + if (endptr != comma) + return -EINVAL; + + config->ctl_fd_ack = strtoul(comma + 1, &endptr, 0); + if (endptr == comma + 1 || *endptr != '\0') + return -EINVAL; + } + + return 0; +} + static struct option stat_options[] = { OPT_BOOLEAN('T', "transaction", &transaction_run, "hardware transaction statistics"), @@ -1140,6 +1169,10 @@ static struct option stat_options[] = { "libpfm4 event selector. use 'perf list' to list available events", parse_libpfm_events_option), #endif + OPT_CALLBACK(0, "control", &stat_config, "fd:ctl-fd[,ack-fd]", + "Listen on ctl-fd descriptor for command to control measurement ('enable': enable events, 'disable': disable events).\n" + "\t\t\t Optionally send control command completion ('ack\\n') to ack-fd descriptor.", + parse_control_option), OPT_END() }; @@ -2309,6 +2342,9 @@ int cmd_stat(int argc, const char **argv) signal(SIGALRM, skip_signal); signal(SIGABRT, skip_signal); + if (evlist__initialize_ctlfd(evsel_list, stat_config.ctl_fd, stat_config.ctl_fd_ack)) + goto out; + status = 0; for (run_idx = 0; forever || run_idx < stat_config.run_count; run_idx++) { if (stat_config.run_count != 1 && verbose > 0) @@ -2328,6 +2364,8 @@ int cmd_stat(int argc, const char **argv) if (!forever && status != -1 && (!interval || stat_config.summary)) print_counters(NULL, argc, argv); + evlist__finalize_ctlfd(evsel_list); + if (STAT_RECORD) { /* * We synthesize the kernel mmap record just so that older tools diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h index 41d59f1..f8778cf 100644 --- a/tools/perf/util/stat.h +++ b/tools/perf/util/stat.h @@ -133,6 +133,8 @@ struct perf_stat_config { struct perf_cpu_map *cpus_aggr_map; u64 *walltime_run; struct rblist metric_events; + int ctl_fd; + int ctl_fd_ack; }; void perf_stat__set_big_num(int set); -- 2.7.4