#!/usr/bin/stap
#
# Copyright (C) 2018 Red Hat, Inc.
# By William Cohen, Red Hat Inc.
# [email protected]
#
# USAGE: stap syscalllatencybypid.stp --suppress-handler-errors
#
# The "--suppress-handler-errors" option allows the script to continue
# run when probes are skipped.  The probe skips make the data less accurate,
# but are otherwise harmless.

global arr%[20000], sys%[20000], entry_time%[20000]

probe syscall_any {
    entry_time[tid()] = gettimeofday_ns();
    sys[tid()] = syscall_nr
}
probe syscall_any.return {
    et = entry_time[tid()]
    id = sys[tid()]
    delete entry_time[tid()]
    delete sys[tid()]
    if (et)
       arr[pid(), id] += (gettimeofday_ns() - et)
}

probe scheduler.process_exit { delete arr[pid(),*] }

function ns2sec:string(v:long) {
    return sprintf("%d.%d", v/1000000000, v%1000000000)
}

probe prometheus {
    @prometheus_dump_array2_map(arr, "syscall_time", "pid", "syscall",
                                ns2sec, sprint, syscall_name)
}