Files
s390-tools/cpacfstats/cpacfstatsd.8
Marc Hartmayer 70cb25766b cpacfstatsd: manpage: CPU hotplug is recognized by the daemon
Since commit 72b5e8b313 ("cpacfstats: Handle CPU hotplug") CPU
hotplugs are recognized by the daemon.

Fixes: 72b5e8b313 ("cpacfstats: Handle CPU hotplug")
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2023-07-04 15:41:03 +02:00

100 lines
3.3 KiB
Groff

.\" cpacfstatsd.8
.\"
.\" Copyright IBM Corp. 2015, 2020
.\" s390-tools is free software; you can redistribute it and/or modify
.\" it under the terms of the MIT license. See LICENSE for details.
.\"
.\" use
.\" groff -man -Tutf8 cpacfstatsd.8
.\" or
.\" nroff -man cpacfstatsd.8
.\" to process this source
.\"
.TH cpacfstatsd "8" "January 2015" "s390-tools"
.
.ds c \fcpacfstatsd\fP
.
.SH NAME
cpacfstatsd \- CPACF statistics collection daemon process
.
.SH SYNOPSIS
.B cpacfstatsd
.RB [ \-h | \-\-help ]
.RB [ \-v | \-\-version ]
.RB [ \-f | \-\-foreground ]
.
.SH DESCRIPTION
The cpacfstatsd controlling daemon enables, disables, resets, and fetches
the mainframe CPACF performance counter registers.
The daemon receives commands from the user application cpacfstats through
the UNIX Domain Socket, processes them and returns the requested
information. For all available commands, see the cpacfstats man page.
Prerequisites
.P
- The running Linux kernel must have the the CONFIG_PERF_EVENTS
config option enabled.
.P
- Libpfm version 4 or higher is needed to successfully run the daemon.
.P
- On the HMC or SE, authorize the LPAR for each counter set you want
to use. Customize the LPAR activation profile and modify the Counter
Facility Security Options. You need to activate the "Crypto activity
counter set authorization control" checkbox.
.P
- The daemon requires root privileges to interact with the performance
ioctls of the kernel.
CPU hotplug is recognized by the daemon. When adding or removing a CPU,
the daemon ensures correct summing of the per-CPU performance counters.
The starting daemon first checks for any stale pid file
\%/run/cpacfstatsd.pid. If this file exists, and the process ID in the
file belongs to an active process, an error message is printed to the
console and the program terminates.
The daemon and the client cpacfstats communicate through a Unix Domain
Socket. This socket is created by the daemon at startup with the associated
socket file /run/cpacfstatsd_socket. For security reasons only members of
the group \fIcpacfstats\fR are allowed to communicate with the daemon. A
system administrator should create this group and add all users which are
allowed to run the cpacfstats client to the group.
After startup, the daemon runs in the background and detaches from any
terminal. Errors and warnings are posted to the syslog subsystem. Check the
process list and the system syslog messages for confirmation of successful
startup.
On regular termination the pid file, the communication socket and the
associated file is removed gracefully.
.SH OPTIONS
.TP
\fB\-h\fR or \fB\-\-help\fR
Display help information for the command.
.TP
\fB\-v\fR or \fB\-\-version\fR
Display version and copyright information for the command.
.TP
\fB\-f\fR or \fB\-\-foreground\fR
Run the daemon in foreground mode, thus printing errors to stderr instead
of posting them through syslog. This option might be useful when debugging
daemon startup and initialization failures.
.SH FILES
.nf
/run/cpacfstatsd_socket
/run/cpacfstatsd.pid
.fi
.SH RETURN VALUE
.IP 0
The daemon was successfully set to run in the background. This does not
imply that the daemon startup was successful, as the main initialization is
done in the re-spawned process. Check the syslog for success or failure.
.IP 1
The daemon could not be set to run in the background.
.SH SEE ALSO
.BR cpacfstats (1)