Ingens

Coordinated and Efficient Huge Page Management system.

Details are in a OSDI paper: http://www.cs.utexas.edu/~yjkwon/pdf/kwon16osdi-ingens.pdf

Components

linux-4.3.0-ingens : Ingens Linux kernel

ingens.diff : Kernel (based on v4.3.0) patches of Ingens

scripts : experiment scripts

programs : Various programs and tools for experiments

benchmarks : some benchmarks used in the paper (To be uploaded)

Ingens kernel build.

An example of configuration file is "memory.config" in linux-4.3-ingens.

Ingens uses linux idle page tracking. (http://lxr.free-electrons.com/source/Documentation/vm/idle_page_tracking.txt)

Make sure to set CONFIG_IDLE_PAGE_TRACKING=y in your kbuild configuration.

Parameters

List of configurable policy parameters

/sys/kernel/mm/transparent_hugepage/ingens/

• deferred_mode

0 : Unmodified Linux

1 : Ingens without sampling address for access bit tracking

2 : Ingens with sampling address for access bit tracking

3 : Frequency-based promotion; Experimental and Unused

e.g., echo 2 > /sys/kernel/mm/transparent_hugepage/ingens/deferred_mode

• util_threshold

utilization threshold (0 < util_threshold <= 100)

• scan_sleep_millisecs

Sleep interval for each access bit profiling in milliseconds

• compact_sleep_millisecs

Sleep interval for proactive compaction in milliseconds

0 : disable proactive compaction

• fairness

0 : Turn off huge page promotion

1 : Enable fair huge page promotion

/sys/kernel/mm/ksm/

• run

0 : Disable identical page sharing

1 : Linux identical page sharing

2 : Huge identical page sharing

3 : Huge page reservation based page sharing (experimental)

4 : Ingens coordinated page sharing

Experimental

• /sys/kernel/mm/transparent_hugepage/ingens/distance_divisor
• /sys/kernel/mm/transparent_hugepage/ingens/aggregation_sleep_millisecs

Ingens features

Used features

• Asynchronous promotion
• Utilization-based promotion
• Fair huge page promotion
• Identical Huge page sharing
• Coordinated huge page sharing
• Proactive compaction
• Hot/cold page identification
• Huge page aligned mmap
• TCmalloc improvement for huge page allocation

Experimental features

• Fair LRU eviction for swapping
• Guest physical page aggregration
• Auto-ballooning using memory pressure notification API

Contributors

Youngjin Kwon ([email protected])

Hangchen Yu ([email protected])

License

GPLv2 License