From 3d08cd331c1adcf0d917392f7e527b3f00511748 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 May 2024 06:52:22 +0200 Subject: Merging upstream version 6.8. Signed-off-by: Daniel Baumann --- man/man2/s390_runtime_instr.2 | 104 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 104 insertions(+) create mode 100644 man/man2/s390_runtime_instr.2 (limited to 'man/man2/s390_runtime_instr.2') diff --git a/man/man2/s390_runtime_instr.2 b/man/man2/s390_runtime_instr.2 new file mode 100644 index 0000000..1d52848 --- /dev/null +++ b/man/man2/s390_runtime_instr.2 @@ -0,0 +1,104 @@ +.\" Copyright (c) IBM Corp. 2012 +.\" Author: Jan Glauber +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.TH s390_runtime_instr 2 2024-05-02 "Linux man-pages (unreleased)" +.SH NAME +s390_runtime_instr \- enable/disable s390 CPU run-time instrumentation +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.BR "#include " " /* Definition of " S390_* " constants */" +.BR "#include " " /* Definition of " SYS_* " constants */" +.B #include +.P +.BI "int syscall(SYS_s390_runtime_instr, int " command ", int " signum ); +.fi +.P +.IR Note : +glibc provides no wrapper for +.BR s390_runtime_instr (), +necessitating the use of +.BR syscall (2). +.SH DESCRIPTION +The +.BR s390_runtime_instr () +system call starts or stops CPU run-time instrumentation for the +calling thread. +.P +The +.I command +argument controls whether run-time instrumentation is started +.RB ( S390_RUNTIME_INSTR_START , +1) or stopped +.RB ( S390_RUNTIME_INSTR_STOP , +2) for the calling thread. +.P +The +.I 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; +.\" commit b38feccd663b55ab07116208b68e1ffc7c3c7e78 +thus, in current kernels, this argument is ignored. +.SH RETURN VALUE +On success, +.BR 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 +.I errno +is set to indicate the error. +.SH ERRORS +.TP +.B EINVAL +The value specified in +.I command +is not a valid command. +.TP +.B EINVAL +The value specified in +.I signum +is not a real-time signal number. +From Linux 4.4 onwards, the +.I signum +argument has no effect, +so that an invalid signal number will not result in an error. +.TP +.B ENOMEM +Allocating memory for the run-time instrumentation control block failed. +.TP +.B EOPNOTSUPP +The run-time instrumentation facility is not available. +.SH STANDARDS +Linux on s390. +.SH HISTORY +Linux 3.7. +System z EC12. +.SH NOTES +The +.I asm/runtime_instr.h +header file is available +.\" commit df2f815a7df7edb5335a3bdeee6a8f9f6f9c35c4 +since Linux 4.16. +.P +Starting with Linux 4.4, +support for signalling was removed, as was the check whether +.I signum +is a valid real-time signal. +For backwards compatibility with older kernels, it is recommended to pass +a valid real-time signal number in +.I signum +and install a handler for that signal. +.SH SEE ALSO +.BR syscall (2), +.BR signal (7) -- cgit v1.2.3