From 34ff636f322c6d5e4f0a52338fa63a7dff09a495 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Sat, 18 Jul 2026 13:15:36 -0400 Subject: scftorture: Count single_rpc offline failures in statistics output scf_torture_stats_print() aggregates each invoker thread's counters into a local scf_statistics structure before printing, but the n_single_rpc_ofl field is missing from the aggregation loop. As a result, the "single_rpc_ofl" value printed in the statistics line is always zero, even when smp_call_function_single() invocations for the RPC test have failed due to offline CPUs and been counted by the invoker threads. Add the missing accumulation so that the printed value reflects the actual counts. Signed-off-by: Joel Fernandes Signed-off-by: Paul E. McKenney --- tools/perf/python/twatch.py | 61 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100755 tools/perf/python/twatch.py (limited to 'tools/perf/python/twatch.py') diff --git a/tools/perf/python/twatch.py b/tools/perf/python/twatch.py new file mode 100755 index 000000000..04f3db29b --- /dev/null +++ b/tools/perf/python/twatch.py @@ -0,0 +1,61 @@ +#! /usr/bin/env python +# SPDX-License-Identifier: GPL-2.0-only +# -*- python -*- +# -*- coding: utf-8 -*- +# twatch - Experimental use of the perf python interface +# Copyright (C) 2011 Arnaldo Carvalho de Melo +# + +import perf + +def main(context_switch = 0, thread = -1): + cpus = perf.cpu_map() + threads = perf.thread_map(thread) + evsel = perf.evsel(type = perf.TYPE_SOFTWARE, + config = perf.COUNT_SW_DUMMY, + task = 1, comm = 1, mmap = 0, freq = 0, + wakeup_events = 1, watermark = 1, + sample_id_all = 1, context_switch = context_switch, + sample_type = perf.SAMPLE_PERIOD | perf.SAMPLE_TID | perf.SAMPLE_CPU) + + """What we want are just the PERF_RECORD_ lifetime events for threads, + using the default, PERF_TYPE_HARDWARE + PERF_COUNT_HW_CYCLES & freq=1 + (the default), makes perf reenable irq_vectors:local_timer_entry, when + disabling nohz, not good for some use cases where all we want is to get + threads comes and goes... So use (perf.TYPE_SOFTWARE, perf_COUNT_SW_DUMMY, + freq=0) instead.""" + + evsel.open(cpus = cpus, threads = threads); + evlist = perf.evlist(cpus, threads) + evlist.add(evsel) + evlist.mmap() + while True: + evlist.poll(timeout = -1) + for cpu in cpus: + event = evlist.read_on_cpu(cpu) + if not event: + continue + print("cpu: {0}, pid: {1}, tid: {2} {3}".format(event.sample_cpu, + event.sample_pid, + event.sample_tid, + event)) + +if __name__ == '__main__': + """ + To test the PERF_RECORD_SWITCH record, pick a pid and replace + in the following line. + + Example output: + +cpu: 3, pid: 31463, tid: 31593 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31593, switch_out: 1 } +cpu: 1, pid: 31463, tid: 31489 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31489, switch_out: 1 } +cpu: 2, pid: 31463, tid: 31496 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31496, switch_out: 1 } +cpu: 3, pid: 31463, tid: 31491 { type: context_switch, next_prev_pid: 31463, next_prev_tid: 31491, switch_out: 0 } + + It is possible as well to use event.misc & perf.PERF_RECORD_MISC_SWITCH_OUT + to figure out if this is a context switch in or out of the monitored threads. + + If bored, please add command line option parsing support for these options :-) + """ + # main(context_switch = 1, thread = 31463) + main() -- cgit v1.3.1