kgetrlimit64 Kernel Service

Purpose

Controls maximum system resource consumption.

Library

Standard C Library (libc.a)

Syntax

#include <sys/time.h>
#include <sys/resource.h>

void kgetrlimit64 (Resource1, RLP) int Resource1; struct rlimit64 *RLP;

Parameters

Item	Description
Resource1	The Resource1 parameter can be one of the following values: RLIMIT_AS The maximum size, in bytes, of the total available memory of a process. This limit is enforced by the kernel only if the `XPG_SUS_ENV=ON` environment variable is set in the user's environment before the process is executed. If the `XPG_SUS_ENV` environment variable is not set in the user's environment, the limit is not enforced. RLIMIT_CORE The largest size, in bytes, of a core file that can be created. This limit is enforced by the kernel. If the value of the RLIMIT_FSIZE limit is less than the value of the RLIMIT_CORE limit, the system uses the RLIMIT_FSIZE limit value as the soft limit. RLIMIT_CPU The maximum amount of central processing unit (CPU) time, in seconds, to be used by each process. If a process exceeds its soft CPU limit, the kernel sends a SIGXCPU signal to the process. After the hard limit is reached, the process is killed with SIGXCPU, even if it handles, blocks, or ignores that signal. RLIMIT_DATA The maximum size, in bytes, of the data region for a process. This limit defines how far a program can extend its break value with the sbrk subroutine. This limit is enforced by the kernel. RLIMIT_FSIZE The largest size, in bytes, of any single file that can be created. When a process attempts to write, truncate, or clear beyond its soft RLIMIT_FSIZE limit, the operation fails with the `errno` variable set to EFBIG. If the environment variable `XPG_SUS_ENV=ON` is set in the user's environment before the process is issued, then the SIGXFSZ signal is also generated. RLIMIT_NOFILE This is a number one greater than the maximum value that the system can assign to a newly-created descriptor. RLIMIT_STACK The maximum size, in bytes, of the stack region for a process. This limit defines how far a program stack region can be extended. The system automatically performs stack extension. This limit is enforced by the kernel. When the stack limit is reached, the process receives a SIGSEGV signal. If this signal is not caught by a handler using the signal stack, the signal ends the process. RLIMIT_RSS The maximum size, in bytes, to which the resident set size of a process can grow. This limit is not enforced by the kernel. A process might exceed its soft limit size without being ended.
RLP	Points to the rlimit64 structure where the requested limits are returned by the kgetrlimit64 kernel service.

Item

Description

Resource1

The Resource1 parameter can be one of the following values:

RLIMIT_AS: The maximum size, in bytes, of the total available memory of a process. This limit is enforced by the kernel only if the XPG_SUS_ENV=ON environment variable is set in the user's environment before the process is executed. If the XPG_SUS_ENV environment variable is not set in the user's environment, the limit is not enforced.
RLIMIT_CORE: The largest size, in bytes, of a core file that can be created. This limit is enforced by the kernel. If the value of the RLIMIT_FSIZE limit is less than the value of the RLIMIT_CORE limit, the system uses the RLIMIT_FSIZE limit value as the soft limit.
RLIMIT_CPU: The maximum amount of central processing unit (CPU) time, in seconds, to be used by each process. If a process exceeds its soft CPU limit, the kernel sends a SIGXCPU signal to the process. After the hard limit is reached, the process is killed with SIGXCPU, even if it handles, blocks, or ignores that signal.
RLIMIT_DATA: The maximum size, in bytes, of the data region for a process. This limit defines how far a program can extend its break value with the sbrk subroutine. This limit is enforced by the kernel.
RLIMIT_FSIZE: The largest size, in bytes, of any single file that can be created. When a process attempts to write, truncate, or clear beyond its soft RLIMIT_FSIZE limit, the operation fails with the errno variable set to EFBIG. If the environment variable XPG_SUS_ENV=ON is set in the user's environment before the process is issued, then the SIGXFSZ signal is also generated.
RLIMIT_NOFILE: This is a number one greater than the maximum value that the system can assign to a newly-created descriptor.
RLIMIT_STACK: The maximum size, in bytes, of the stack region for a process. This limit defines how far a program stack region can be extended. The system automatically performs stack extension. This limit is enforced by the kernel. When the stack limit is reached, the process receives a SIGSEGV signal. If this signal is not caught by a handler using the signal stack, the signal ends the process.
RLIMIT_RSS: The maximum size, in bytes, to which the resident set size of a process can grow. This limit is not enforced by the kernel. A process might exceed its soft limit size without being ended.

RLP

Points to the rlimit64 structure where the requested limits are returned by the kgetrlimit64 kernel service.

Description

The kgetrlimit64 kernel service returns the values of limits on system resources used by the current process and its children processes.

Note: The initial values returned by the kgetrlimit64 kernel service are the ulimit values in effect when the process was started. For maxdata programs the initial soft limit for data is set to the lower of data ulimit value or a value corresponding to the number of data segments reserved for data segments.

The rlimit64 structure specifies the hard and soft limits for a resource, as defined in the sys/resource.h file. The RLIM64_INFINITY value defines an infinite value for a limit.

Execution Environment

The kgetrlimit64 kernel service can be called from either the process or interrupt environment.

Return Values

The kgetrlimit64 kernel service has no return values.