Cache-Allocation-Technology

Intel's Cache Allocation Technology

Intel’s Cache Allocation Technology (CAT) helps address shared resource concerns by providing software control of where data is allocated into the last-level cache (LLC), enabling isolation and prioritization of key applications.

Acronyms

CAT : Cache Allocation Technology

CMT : Cache Monitoring Technology

CDP : Code and Data prioritization

CLOS/COS : Class of service

Commands

Monitoring

• Show current configuration

sudo pqos -s -v

• Monitor LLC occupancy for group of cores (e.g. [0-2] and [3-5])

sudo pqos -m "all:[0-2],[3-5];"

Usage

• Set COS 1 to the first 4 cache ways and COS 2 to the next 8 cache ways:

pqos -e "llc:1=0x000f;llc:2=0x0ff0;"

• Set COS 1 on all sockets, COS 2 on socket 0 and 1 and COS 3 on sockets 2 to 3:

pqos -e "llc:1=0x000f;llc@0,1:2=0x0ff0;llc@2-3:3=0x3c"

• Associate cores 0, 2, and 6 to 10 with COS 1 and core 1 to COS 2:

pqos -a "llc:1=0,2,6-10;llc:2=1;"

F.A.Q.

When I try to run the utility I get the following error messages:

WARN: Error opening file '/dev/cpu/0/msr'!

ERROR: CDP detection error!

ERROR: Fatal error encounter in CAT discovery!

ERROR: discover_capabilities() error 1

Error initializing PQoS library!

Run the following command:

sudo modprobe msr