Module memory_planner 

Memory planner for buffer reuse optimization.

This module implements liveness-based memory planning following Tinygrad’s approach. The memory planner analyzes buffer lifetimes across the schedule and reuses buffers with non-overlapping lifetimes, reducing memory consumption.

Algorithm

1. Liveness Analysis: Track first/last appearance of each buffer in schedule
2. Event Timeline: Create sorted alloc/free events (frees before allocs at same step)
3. Pool-Based Allocation: Reuse buffers by (device, dtype, size) key
4. Apply Replacements: Map logical buffers to physical buffers

Structs

BufferKey

Key to identify a buffer within a schedule.

BufferLiveness

Liveness information for a buffer.

BufferPoolKey

Key for buffer pooling - groups buffers that can be reused interchangeably.

MemoryPlannerResult

Result of memory planning.

ReuseDependency

Schedule-order dependency introduced by a physical buffer reuse.

Enums

PlannerMode

Selects the buffer-allocation strategy used by the planner entrypoint.

Functions

apply_buffer_replacements

Apply buffer replacements to the schedule.

apply_reuse_dependencies

Add execution-order edges required by physical buffer reuse.

memory_planner

Run memory planner on a schedule.

mode_from_env

Read SVOD_MEMORY_PLANNER from the environment and resolve to a PlannerMode.

parse_mode

Pure parser for the SVOD_MEMORY_PLANNER env var, exposed for testing.