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MEMCONFIG(8) System Manager's Manual MEMCONFIG(8)

memconfigcontrol system cache behaviour with respect to memory

memconfig list [-a]

memconfig set -b base -l length -o owner attribute

memconfig clear -o owner

memconfig clear -b base -l length

A number of supported system architectures allow the behaviour of the CPU cache to be programmed to behave differently depending on the region being written.

memconfig provides an interface to this facility, allowing CPU cache behavior to be altered for ranges of system physical memory.

These ranges are typically power-of-2 aligned and sized, however the specific rules governing their layout vary between architectures. The memconfig program does not attempt to enforce these rules, however the system will reject any attempt to set an illegal combination.

The operands and their options are as follows:

List range slots.
List all range slots, even those that are inactive.
Set memory range attributes.
Memory range base address.
Length of memory range in bytes, power of 2.
Text identifier for this setting (7 char max).
Attributes applied to this range; combinations of force, uncacheable, write-combine, write-through, write-back, or write-protect.
Clear memory range attributes. Ranges may be cleared by owner or by base/length combination.

To clear based on ownership:

All ranges with this owner will be cleared.

To clear based on the base/length combination:

Memory range base address.
Length of memory range in bytes, power of 2.

Base and length must exactly match an existing range.


memconfig was originally introduced in FreeBSD 3.3 as .

January 20, 2014 OpenBSD-7.4