MemGuard: Memory Bandwidth Reservation System

Heechul Yun (heechul@illinois.edu)

Preparation

Recommended kernel settings are as follows:

CONFIG_ACPI_PROCESSOR=n
CONFIG_CPU_IDLE=n

Install

# make
# insmod memguard.ko	
    <-- Load the module by doing

Usage

Once the module is loaded, it provides several configuration interfaces as follows:

- per-core bandwidth assignment.

assign 900,100,100,100 MB/s for Core 0,1,2,3
# echo mb 900 100 100 100 > /sys/kernel/debug/memguard/limit

assign 70%,10%,10%,10% of guaranteed bandwidth(r_min) for Core 0,1,2,3
# echo 70 10 10 10 > /sys/kernel/debug/memguard/limit

assign weights(1:2:4:8) for Core 0,1,2,3
# echo 1 2 4 8 > /sys/kernel/debug/memguard/share


- per-task mode (use task priority as core's memory weight)

enable per-task mode
# echo taskprio 1 > /sys/kernel/debug/memguard/control

disble per-task mode (=per-core mode)
# echo taskprio 0 > /sys/kernel/debug/memguard/control


- set maxbw (r_min in the paper)

# echo maxbw 1200 > /sys/kernel/debug/memguard/control


- reclaim control

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

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


- exclusive mode control

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

last exclusive. last core exclusively use the rest b/w (not in the paper)
# echo exclusive 1 > /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 submission)  
# echo exclusive 5 > /sys/kernel/debug/memguard/control