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_RUNTIME_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.

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

SEE ALSO

       syscall(2), signal(7)

COLOPHON

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       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                          2019-03-06                              S390_RUNTIME_INSTR(2)