0f9b9e9606
* BLS sig: parallel batch verification * BLS: speedup parallel batch verify with Miller loops on local threads * shutdown bench * nit: import style * implement parallel KZG * Parallel KZG commitments * add benchmarks of KZG * rename protocol file * small optim: reorder await * fix rebase * Faster parallel BLS verification * fix commitment status replacing previous error in verify_blob_kzg_proof_batch_parallel * 2x faster parallel EC sum for less than 8192 points |
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| benchmarks | ||
| crossthread | ||
| demos/raytracing | ||
| docs | ||
| examples | ||
| primitives | ||
| README.md | ||
| instrumentation.nim | ||
| parallel_offloading.nim | ||
| partitioners.nim | ||
| threadpool.nim | ||
README.md
Constantine Threadpool
API
The API spec follows https://github.com/nim-lang/RFCs/issues/347#task-parallelism-api
Overview
This implements a lightweight, energy-efficient, easily auditable multithreaded threadpool.
This threadpool will desirable properties are:
- Ease of auditing and maintenance.
- Resource-efficient. Threads spindown to save power, low memory use.
- Decent performance and scalability. The CPU should spent its time processing user workloads and not dealing with threadpool contention, latencies and overheads.
Compared to Weave, here are the tradeoffs:
- Constantine's threadpool provides spawn/sync (task parallelism)
and optimized parallelFor for (data parallelism).
It however does not provide precise in/out dependencies (events / dataflow parallelism). - Constantine's threadpool has been significantly optimized to provide overhead lower than Weave's default (and as low as Weave "lazy" + "alloca" allocation scheme).
Compared to nim-taskpools, here are the tradeoffs:
- Constantine does not use std/tasks:
- No external dependencies at runtime (apart from compilers, OS and drivers)
- We can replace Task with an intrusive linked list
- Furthermore we can embed tasks in their future
- Hence allocation/scheduler overhead is 3x less than nim-taskpools as we fuse the following allocations:
- Task
- The linked list of tasks
- The future (Flowvar) result channel
- Contention improvement, Constantine is entirely lock-free while Nim-taskpools need a lock+condition variable for putting threads to sleep
- Powersaving improvement, threads sleep when awaiting for a task and there is no work available.
- Scheduling improvement, Constantine's threadpool incorporate Weave's adaptative scheduling policy with additional enhancement (leapfrogging)
See also design.md