memcontrol8
Control system cache behaviour with respect to memory
Usage
memcontrol list
[-a]
memcontrol set
-b
base
-l
length
-o
owner
attribute
memcontrol clear
-o
owner
memcontrol clear
-b
base
-l
length
Overview
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.
The memcontrol utility 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 memcontrol utility does not attempt to enforce these rules, however the system will reject any attempt to set an illegal combination.
list-
List range slots.
-
-a -
List all range slots, even those that are inactive.
-
set-
Set memory range attributes.
-
-b base -
Memory range base address.
-
-l length -
Length of memory range in bytes, power of 2.
-
-o owner -
Text identifier for this setting (7 char max).
- attribute
-
Attributes applied to this range; combinations of
force,uncacheable,write-combine,write-through,write-back, andwrite-protect.
-
clear-
Clear memory range attributes. Ranges may be cleared by owner or by base/length combination.
To clear based on ownership:
-
-o owner -
All ranges with this owner will be cleared.
To clear based on the base/length combination:
-
-b base -
Memory range base address.
-
-l length -
Length of memory range in bytes, power of 2.
Base and length must exactly match an existing range.
-
-
Releases
73 releases since FreeBSD 3.4-RELEASE; the text changed 39 times.
- 3.4
- 3.5–3.5.1
- 4.0–4.2
- 4.3
- 4.4–4.6.2
- 4.7
- 4.8–4.11
- 5.0–6.3
- 6.4
- 7.0
- 7.1
- 7.2
- 7.3
- 7.4
- 8.0
- 8.1
- 8.2
- 8.3
- 8.4
- 9.0
- 9.1
- 9.2
- 9.3
- 10.0
- 10.1
- 10.2
- 10.3
- 10.4
- 11.0
- 11.1
- 11.2
- 11.3
- 11.4
- 12.0
- 12.1
- 12.2
- 12.3
- 12.4
- 13.0–13.2
- 13.3–16.0
-a since FreeBSD 4.8-RELEASE.