S390_RUNTIME_INSTR(2)                                    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
       instrumentation for the calling thread.

       The command  argument  controls  whether  run-time  instrumentation  is
       started    (S390_RUNTIME_INSTR_START,    1)   or   stopped   (S390_RUN-
       TIME_INSTR_STOP, 2) for the calling thread.

       The signum argument specifies the number of a  real-time  signal.   The
       real-time  signal is sent to the thread if the run-time instrumentation
       buffer is full  or  if  the  run-time-instrumentation-halted  interrupt
       occurred.

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
       instrumentation 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 or the
              value specified in signum is not a real-time signal number.

       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.

SEE ALSO
       syscall(2), signal(7)

COLOPHON
       This page is part of release 4.16 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         2017-09-15             S390_RUNTIME_INSTR(2)