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 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 architecture.  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 4.15 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)