S390_RUNTIME_INSTR(2)



S390_RUNTIME_INSTR(2)         System Calls Manual        S390_RUNTIME_INSTR(2)

NAME
       s390_runtime_instr - enable/disable s390 CPU run-time instrumentation

SYNOPSIS
       #include <asm/runtime_instr.h>

       int s390_runtime_instr(int command, int signum);

DESCRIPTION
       The  s390_runtime_instr()  system call starts or stops CPU run-time in-
       strumentation for the calling thread.

       The command  argument  controls  whether  run-time  instrumentation  is
       started  (S390_RUNTIME_INSTR_START,  1)  or  stopped  (S390_RUNTIME_IN-
       STR_STOP, 2) for the calling thread.

       The signum argument specifies the number of a real-time  signal.   This
       argument  was  used to specify a signal number that should be delivered
       to the thread if the run-time instrumentation buffer was full or if the
       run-time-instrumentation-halted  interrupt  had occurred.  This feature
       was never used, and in Linux 4.4 support for this feature was  removed;
       thus, in current kernels, this argument is ignored.

RETURN VALUE
       On  success,  s390_runtime_instr() returns 0 and enables the thread for
       run-time instrumentation by assigning the thread a default run-time in-
       strumentation  control  block.  The caller can then read and modify the
       control block and start the run-time instrumentation.  On error, -1  is
       returned and errno is set to one of the error codes listed below.

ERRORS
       EINVAL The value specified in command is not a valid command.

       EINVAL The  value specified in signum is not a real-time signal number.
              From Linux 4.4 onwards, the signum argument has  no  effect,  so
              that an invalid signal number will not result in an error.

       ENOMEM Allocating memory for the run-time instrumentation control block
              failed.

       EOPNOTSUPP
              The run-time instrumentation facility is not available.

VERSIONS
       This system call is available since Linux 3.7.

CONFORMING TO
       This Linux-specific system call is available only on the s390 architec-
       ture.   The  run-time  instrumentation  facility is available beginning
       with System z EC12.

NOTES
       Glibc does not provide a wrapper for this system call,  use  syscall(2)
       to call it.

       The asm/runtime_instr.h header file is available since Linux 4.16.

       Starting with Linux 4.4, support for signalling was removed, as was the
       check whether signum is a valid real-time signal.  For  backwards  com-
       patibility  with older kernels, it is recommended to pass a valid real-
       time signal number in signum and install a handler for that signal.

SEE ALSO
       syscall(2), signal(7)

COLOPHON
       This page is part of release 5.07 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.

Linux Programmer's Manual         2020-06-09             S390_RUNTIME_INSTR(2)

Man(1) output converted with man2html
list of all man pages