#! /usr/bin/env python# SPDX-License-Identifier: GPL-2.0# -*- python -*-# -*- coding: utf-8 -*- import perf def change_proctitle():    try:        import setproctitle        setproctitle.setproctitle("tracepoint.py")    except:        print("Install the setproctitle python package to help with top and friends") def main():    change_proctitle()    cpus    = perf.cpu_map()    threads = perf.thread_map(-1)    evlist = perf.parse_events("sched:sched_switch", cpus, threads)    # Disable tracking of mmaps and similar that are unnecessary.    for ev in evlist:        ev.tracking = False    # Configure evsels with default record options.    evlist.config()    # Simplify the sample_type and read_format of evsels    for ev in evlist:        ev.sample_type = ev.sample_type & ~perf.SAMPLE_IP        ev.read_format = 0     evlist.open()    evlist.mmap()    evlist.enable();     while True:        evlist.poll(timeout = -1)        for cpu in cpus:            event = evlist.read_on_cpu(cpu)            if not event:                continue             if not isinstance(event, perf.sample_event):                continue             print("time %u prev_comm=%s prev_pid=%d prev_prio=%d prev_state=0x%x ==> next_comm=%s next_pid=%d next_prio=%d" % (                   event.sample_time,                   event.prev_comm,                   event.prev_pid,                   event.prev_prio,                   event.prev_state,                   event.next_comm,                   event.next_pid,                   event.next_prio)) if __name__ == '__main__':    main()