For the complete documentation index, see llms.txt. Markdown versions of all pages are available by appending .md to any URL (e.g. /max/get-started.md).

Mojo struct

ScheduleConfig

struct ScheduleConfig

Tunable parameters for schedule generation.

Controls the structural decisions in program builders: scheduling strategy, barrier placement, and drain behavior.

The default configuration auto-derives wait counts from the program structure (Halide-inspired: declare intent, derive consequences). Manual wait overrides are available for testing and experimentation but should not be needed for correct operation.

Fields

• ​scheduling (SchedulingStrategy): The strategy for op ordering (IDENTITY, GREEDY, or CSP).
• ​sched_barrier_mask (Int): The bitmask of blocks that get trailing schedule_barrier fences. Default: 0b01010101 (blocks 0, 2, 4, 6).
• ​auto_waits (Bool): Whether to auto-derive wait counts from schedule order.
• ​drain_lgkm_mask (Int): The per-block bitmask for selective LDS drains.
• ​auto_drain (Bool): Whether to auto-derive the drain mask from channel analysis.
• ​lds_contention_penalty (Int): The CSP solver penalty for LDS port overlap.
• ​wait_lgkm_first (Int): The manual wait_lgkm(N) override (used when auto_waits=False).
• ​wait_vm_last (Int): The manual wait_vm(N) override (used when auto_waits=False).
• ​lgkm_per_load_a (Int): The number of lgkmcnt ops per channel-A load (for wait derivation).
• ​lgkm_per_load_b (Int): The number of lgkmcnt ops per channel-B load (for wait derivation).
• ​lgkm_after_last (Bool): Whether to insert wait_lgkm(0) after the last block barrier.
• ​minimal_barriers (Bool): Whether to suppress per-block s_barriers and set_prio pairs and emit s_barrier only at top-of-half and the first cross-stage block.
• ​omit_mma_set_prio (Bool): When minimal_barriers=True, whether to drop the pre-MMA s_setprio[1] entirely so the LLVM register allocator can reuse VGPRs across it.
• ​max_vgpr (Int): The hint for the cost model on the kernel's VGPR budget. Default is effectively unlimited.
• ​global_before_frag (Bool): Whether to swap the in-block emission order of global loads and fragment loads. Default emits frags first then prefetches.
• ​barrier_before_pre_ops (Bool): Whether to move the per-block pre_sync + barrier section before the frag/prefetch section instead of between prefetch and MMA.
• ​inter_block_lgkm_drain (Bool): Whether to populate entry_wait_lgkm on non-top, non-cross-stage blocks with wait_lgkm(0) so an inter-mini LDS drain fires between consecutive same-half MMAs.
• ​wrap_waits_with_sched_barrier (Bool): Whether to wrap each contiguous wait/barrier group with schedule_barrier() on both sides to fence the LLVM machine scheduler.
• ​partial_prologue_drain (Bool): Whether to skip the framework prologue's wait_vm(0) drains and inter-stage barrier so prefetches stay in flight on entry to the kernel.

Implemented traits

AnyType, Copyable, ImplicitlyCopyable, ImplicitlyDeletable, Movable

Methods

__init__

def __init__(out self, *, scheduling: SchedulingStrategy = SchedulingStrategy.IDENTITY, sched_barrier_mask: Int = 85, auto_waits: Bool = True, drain_lgkm_mask: Int = 0, auto_drain: Bool = False, lds_contention_penalty: Int = 0, wait_lgkm_first: Int = 8, wait_vm_last: Int = 6, lgkm_per_load_a: Int = 0, lgkm_per_load_b: Int = 0, lgkm_after_last: Bool = False, minimal_barriers: Bool = False, omit_mma_set_prio: Bool = False, max_vgpr: Int = 999999, global_before_frag: Bool = False, barrier_before_pre_ops: Bool = False, inter_block_lgkm_drain: Bool = False, partial_prologue_drain: Bool = False, wrap_waits_with_sched_barrier: Bool = False)

from_strategies

static def from_strategies(*, scheduling: SchedulingStrategy = SchedulingStrategy.IDENTITY, max_vgpr: Int = 999999, lds_contention_penalty: Int = 0, minimal_barriers: Bool = False, omit_mma_set_prio: Bool = False, sched_barrier_mask: Int = 85, wrap_waits_with_sched_barrier: Bool = False, barrier_before_pre_ops: Bool = False, auto_waits: Bool = True, drain_lgkm_mask: Int = 0, auto_drain: Bool = False, wait_lgkm_first: Int = 8, wait_vm_last: Int = 6, lgkm_after_last: Bool = False, inter_block_lgkm_drain: Bool = False, partial_prologue_drain: Bool = False, global_before_frag: Bool = False, lgkm_per_load_a: Int = 0, lgkm_per_load_b: Int = 0) -> Self

Constructs a ScheduleConfig from grouped strategy values.

Equivalent to the flat-field constructor but groups related flags by phase (barrier / wait / load). pipeline.strategies provides named factories (BarrierStrategy.minimal_no_set_prio etc.) that callers can spread into this constructor.

Existing flat-field callers continue to work unchanged.

Args:

• ​scheduling (SchedulingStrategy): CSP solver scheduling strategy.
• ​max_vgpr (Int): VGPR budget hint for the cost model.
• ​lds_contention_penalty (Int): Penalty for LDS port overlap.
• ​minimal_barriers (Bool): Suppress per-block s_barriers and set_prio pairs.
• ​omit_mma_set_prio (Bool): Drop the pre-MMA s_setprio[1] when minimal_barriers=True.
• ​sched_barrier_mask (Int): Bitmask of which blocks get trailing schedule_barrier fences.
• ​wrap_waits_with_sched_barrier (Bool): Wrap each contiguous wait/barrier group with schedule_barrier.
• ​barrier_before_pre_ops (Bool): Move pre_sync + barrier ahead of the frag/global section.
• ​auto_waits (Bool): Auto-derive wait counts from program structure.
• ​drain_lgkm_mask (Int): Per-block bitmask for selective LDS drains.
• ​auto_drain (Bool): Auto-derive drain_lgkm_mask from channel analysis.
• ​wait_lgkm_first (Int): Manual wait_lgkm override.
• ​wait_vm_last (Int): Manual wait_vm override for the last block.
• ​lgkm_after_last (Bool): Insert wait_lgkm(0) after the last block's barrier.
• ​inter_block_lgkm_drain (Bool): Emit wait_lgkm(0) at non-top, non-cross interior block starts.
• ​partial_prologue_drain (Bool): Skip wait_vm(0) drains in the framework prologue.
• ​global_before_frag (Bool): Emit globals before frags in each block.
• ​lgkm_per_load_a (Int): lgkmcnt entries per channel-A frag-load.
• ​lgkm_per_load_b (Int): lgkmcnt entries per channel-B frag-load.

Returns:

Self: A fully populated ScheduleConfig.

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