> For the complete documentation index, see [llms.txt](https://docs.aios.foundation/aios-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.aios.foundation/aios-docs/aios-kernel/scheduler.md). # Scheduler Instead of placing separate queues within each processing module (e.g., LLM core(s) or memory manager), we centralize all the queues within the scheduler module. This aims to isolate the responsibility for request management from the individual modules, allowing each processing module to focus on its execution and simplifies the coordination of tasks across modules.

AIOS Scheduler manages the Request queue for each module, the Request queue includes both Queries (agent-to-kernel request) and Messages (module-to-module request)

The main purpose of the scheduler is to serve different agents queries in a fine-grained granularity (i.e., syscall level granuity) as below.

Scheduling example for syscalls for different agents (use LLM Syscall for illustration simplicity)

AIOS provides two main scheduler implementations to manage system calls from agents: | Feature | FIFOScheduler | RRScheduler | | ---------------------- | ------------------------------ | ---------------------------------- | | **Task Selection** | First-come, first-served | Round-robin rotation | | **Time Management** | No time limit enforcement | Fixed time slices per task | | **Task Preemption** | None (tasks run to completion) | Tasks can be suspended and resumed | | **Status Handling** | Only "executing"/"done" | "executing"/"done"/"suspending" | | **Context Management** | None | Uses SimpleContextManager | ### BaseScheduler The `BaseScheduler` is an abstract base class that defines the common interface and functionality for all scheduler implementations in AIOS. #### Abstract Methods | Method | Description | | ---------------------------- | ---------------------------------------------- | | `start_processing_threads()` | Start threads for different request processors | | `stop_processing_threads()` | Stop all processing threads gracefully | | `process_llm_requests()` | Abstract method to process LLM requests | | `process_memory_requests()` | Abstract method to process Memory requests | | `process_storage_requests()` | Abstract method to process Storage requests | | `process_tool_requests()` | Abstract method to process Tool requests | | `start()` | Abstract method to start the scheduler | | `stop()` | Abstract method to stop the scheduler | ### Different scheduler implementations * [FIFO Scheduler](/aios-docs/aios-kernel/scheduler/fifoscheduler.md) * [RR Scheduler](/aios-docs/aios-kernel/scheduler/rrscheduler.md)