boot_cpuset(4)boot_cpuset(4)NAME
boot_cpuset.conf, boot_cpuset.so - boot cpuset configuration tool
SYNOPSIS
boot_cpuset.so is loaded and executed by init
DESCRIPTION
The boot_cpuset.so library provides a method for putting init(1M) into a
cpuset(4). The cpuset that init(1M) will be placed into is named boot.
Since all processes (threads of execution associated with a process
identifier, or PID) are descendents of init(1M), they too will be
confined to the boot cpuset. For a process to execute outside the boot
cpuset, another cpuset must be created and the process placed in the new
cpuset. Then that process, and all processses descended from it after it
is placed in the new cpuset, will execute outside the boot cpuset.
It is sometimes desirable to create a cpuset for system daemons and
kernel threads. This cpuset protects them from starvation and is called
the system cpuset. If this cpuset is created, unbound kernel threads and
NFS server processes will run within it.
The boot_cpuset.so library is normally installed on SGI ccNUMA systems.
If it is found in /lib32 by init, it will be loaded and executed. The
behaviour of the boot cpuset is controlled by /etc/config/boot_cpuset and
/etc/config/boot_cpuset.config. The former file follows the chkconfig(1M)
convention and may be manipulated by chkconfig. If it contains the word
on, creation of the cpuset will proceed unless an error occurs. If off is
found, the library will check if a system cpuset is desired. This is
controlled by the /etc/config/system_cpuset and
/etc/config/system_cpuset.config files. These files operate the same as
the boot cpuset files. The library will lastly exit and normal init
processing will resume. The /etc/config/boot_cpuset.config and
/etc/config/system_cpuset.config files follows the syntax convention of
cpuset(4). All restrictions specified in miser_cpuset(1) apply.
Confinement of bound kernel system and interrupt threads within the boot
or system cpusets may be achieved by using the XThread Control Interface
(XTCI). This is sometimes desirable to keep IRIX kernel level daemons
from competing with applications for certain processors. The XTCI is
documented in the realtime(5) man page.
FILES
/etc/config/boot_cpuset Follows chkconfig(1M) convention.
/etc/config/boot_cpuset.config Configuration file specifying the
cpuset. See cpuset(4) for more
information.
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boot_cpuset(4)boot_cpuset(4)
/etc/config/system_cpuset Follows chkconfig(1M) convention. If
off, no further processing occurs and
init will resume.
/etc/config/system_cpuset.config Configuration file specifying the
cpuset. See cpuset(4) for more
information.
WARNINGS
No attempt is made to check the configuration file for a reasonable
configuration. Specifying an unreasonable configuration may leave system
non-functional.
Note: The cpuset is not activated if the system is booted into single
user mode. This provides an escape mechanism should the configuration
prove to be unreasonable.
When the boot cpuset is defined, processes that are moved out of the
other cpusets do not, by default, return to the boot cpuset. To move
processes from the other cpusets to the boot cpuset, specify the boot
cpuset as the destination for the move operation. (see cpuset(1) for more
information about moving processes between cpusets).
NOTES
Allthough this mechanism can be used in a standalone fashion with the
cpuset(1) command, it is primarily intended for use by batch systems. Due
to the above noted limitation of moving processes between cpusets, it may
not practical to dynamically re-adjust resources for running processes or
jobs.
SEE ALSOinit(1M), miser_cpuset(1), cpuset(4), realtime(5).
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