MemGuard

MemGuard is a memory bandwidth reservation system for multi-core platforms.

ChangeLog

• Dec 2022
  • 5.15+ kernel support
• May 2022
  • read/write separate reservation (from RTAS'19)
  • bandwidth reclaiming (re-enabled. originally from RTAS'13)

Install

- build
# make

- load the module
# insmod memguard.ko

Usage

Once the module is loaded, the thresholds can be set as follows:

- per-core LLC miss threshold assignment.

assign 500 MB/s for Cores 0,1,2,3
# echo mb 500 500 500 500 > /sys/kernel/debug/memguard/read_limit

- per-core LLC writeback threshold assignment.

assign 100 MB/s for Cores 0,1,2,3
# echo mb 100 100 100 100 > /sys/kernel/debug/memguard/write_limit

- reclaim control (of reserved bandwidth)

enable
# echo reclaim 1 > /sys/kernel/debug/memguard/control

disable
# echo reclaim 0 > /sys/kernel/debug/memguard/control

- exclusive mode control (of best-effort bandwidth)

strict reservation. (disable best-effort sharing. only use guaranteed bw)
# echo exclusive 0 > /sys/kernel/debug/memguard/control

spare b/w sharing mode (see RTAS13)
# echo exclusive 2 > /sys/kernel/debug/memguard/control

proportional share mode (see TC'15)
# echo exclusive 5 > /sys/kernel/debug/memguard/control