Adopt specialized autochunking allocator to support dynamic allocation #2
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The autochunking allocator has some interesting properties: - O(1) allocation and deallocation - zero fragmentation for same-sized allocations - no external fragmentation over time The biggest downside of the allocator is that the allocator performs no coalescing. This can create excessive fragmentation when used with a large number of different-sized allocation.
The previous allocator used a finite set of chunk-lists. This had the nice garuntee of strict constant allocation cost, but incurred unnecessary fragmentation once the set was exceeded. By using a linked-list of chunk-lists, this fragmentation can be avoided and the chunk-list scan potenially short-circuited, at the downside of introducing the quantity of different allocation sizes as a variable in the allocation cost.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The autochunking allocator has some interesting properties:
The biggest downside is that the allocator performs no coalescing. This can create excessive fragmentation when used with a large number of different-sized allocation.
When used with a finite set of allocation sizes, this allocator approaches O(1) allocation cost, necessary for interrupt driven systems, and zero fragmentation over time, necessary for long running programs on low-memory systems.
cc @kilogram