Scheduler and Core Isolation

Scheduler and Core Isolation

Purpose

This page describes OSAI's no-migration and hot-core isolation model.

Contents

• No Migration by Default
• Core Leases
• Ticks and Interrupts
• Platform Policies

No Migration by Default

AI hot workers should not migrate unless a service explicitly changes placement.

Target invariant:

core migrations on hot AI paths = 0

Core Leases

Exclusive core leases bind AI Cell workers to declared cores. Leased cores should run only their assigned loop, and unrelated work should stay on housekeeping cores.

Ticks and Interrupts

Hot cores should avoid:

• periodic scheduler ticks;
• unrelated IRQs;
• involuntary context switching;
• background kernel work;
• post-warmup page faults.

Platform Policies

Intel Desktop:

• P-cores: AI inference and low-latency network workers;
• E-cores: SSH, logging, source indexing, Git, build/test, background services;
• SMT siblings disabled or reserved until explicitly enabled.

Intel Xeon:

• keep latency-sensitive AI Cells inside one NUMA node;
• keep NIC and NVMe queues NUMA-local;
• avoid cross-node memory unless configured.

ARM/NVIDIA N1X-compatible:

• highest-performance cores: AI inference;
• middle cores: network/tokenizer workers;
• efficiency cores: SSH, logging, Git, source indexing, build/test;
• cluster migration forbidden for AI hot workers by default.

Related Pages

• AI Cells
• Performance Targets