occlum

History

Hui, Chunyang 6dd73c64b5 Improve userspace VM management Occlum is a single-address-space library OS. Previously, userspace memory are divided for each process. And all the memory are allocated when the process is created, which leads to a lot of wasted space and complicated configuration. In the current implementation, the whole userspace is managed as a memory pool that consists of chunks. There are two kinds of chunks: (1) Single VMA chunk: a chunk with only one VMA. Should be owned by exactly one process. (2) Multi VMA chunk: a chunk with default chunk size and there could be a lot of VMAs in this chunk. Can be used by different processes. This design can help to achieve mainly two goals: (1) Simplify the configuration: Users don't need to configure the process.default_mmap_size anymore. And multiple processes running in the same Occlum instance can use dramatically different sizes of memory. (2) Gain better performance: Two-level management(chunks & VMAs) reduces the time for finding, inserting, deleting, and iterating.	2021-10-17 15:58:29 +08:00
..
main.c	Improve userspace VM management	2021-10-17 15:58:29 +08:00
Makefile	Refactor mmap implementation	2019-07-01 11:56:04 +08:00

Hui, Chunyang 6dd73c64b5 Improve userspace VM management

Occlum is a single-address-space library OS. Previously, userspace memory are divided for each process.
And all the memory are allocated when the process is created, which leads to a lot of wasted space and
complicated configuration.

In the current implementation, the whole userspace is managed as a memory pool that consists of chunks. There
are two kinds of chunks:
(1) Single VMA chunk: a chunk with only one VMA. Should be owned by exactly one process.
(2) Multi VMA chunk: a chunk with default chunk size and there could be a lot of VMAs in this chunk. Can be used
by different processes.

This design can help to achieve mainly two goals:
(1) Simplify the configuration: Users don't need to configure the process.default_mmap_size anymore. And multiple processes
running in the same Occlum instance can use dramatically different sizes of memory.
(2) Gain better performance: Two-level management(chunks & VMAs) reduces the time for finding, inserting, deleting, and iterating.

2021-10-17 15:58:29 +08:00

main.c

Improve userspace VM management

2021-10-17 15:58:29 +08:00

Makefile

Refactor mmap implementation

2019-07-01 11:56:04 +08:00