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chronon::TickSimulationConfig

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#include <TickSimulationConfig.hpp>

Public Types​

Name
enum classPartitionSolverType { Weighted, SA}

Public Attributes​

Name
booltrace_execution
SchedulerTimelineTraceConfigtimeline_trace
uint64_ttick_frequency_hz
1 GHz default.
doublesa_critical_path_weight
doublerebalance_min_gain
Skip rebalance if predicted gain below this fraction.
doublerebalance_imbalance_threshold
uint64_trebalance_cooldown_cycles
Minimum cycles between rebalances (0 disables cooldown).
uint64_trebalance_check_interval_cycles
uint64_tprofiling_warmup_cycles
uint64_tprofiling_measurement_cycles
PartitionSolverTypepartition_solver
size_tnum_threads
uint32_tmax_lookahead_cycles
uint64_tepoch_size
Cycles per epoch before sync.
boolenable_weighted_partitioning
boolenable_parallel
boolenable_lookahead
boolenable_dynamic_rebalance
booldeterministic_partitioning
std::stringcost_profile_cache_path

Detailed Description​

struct chronon::TickSimulationConfig;

Configuration for tick-based simulation.

Placement (initialization-time) vs. scheduling (runtime) are orthogonal. Placement groups units into clusters; scheduling decides how those clusters advance in time. cluster.size() == 1 is the fallback for un-clustered topologies — the scheduler treats the two uniformly.

Public Types Documentation​

enum PartitionSolverType​

EnumeratorValueDescription
Weighted
SA

Public Attributes Documentation​

variable trace_execution​

bool trace_execution = false;

variable timeline_trace​

SchedulerTimelineTraceConfig timeline_trace;

variable tick_frequency_hz​

uint64_t tick_frequency_hz = 1'000'000'000;

1 GHz default.

variable sa_critical_path_weight​

double sa_critical_path_weight = 0.0;

SA objective critical-path term weight applied to max per-thread chain cost (ns). 0 disables the term (default).

variable rebalance_min_gain​

double rebalance_min_gain = 0.05;

Skip rebalance if predicted gain below this fraction.

variable rebalance_imbalance_threshold​

double rebalance_imbalance_threshold = 1.3;

variable rebalance_cooldown_cycles​

uint64_t rebalance_cooldown_cycles =
        0;

Minimum cycles between rebalances (0 disables cooldown).

variable rebalance_check_interval_cycles​

uint64_t rebalance_check_interval_cycles = 8192;

variable profiling_warmup_cycles​

uint64_t profiling_warmup_cycles = 512;

variable profiling_measurement_cycles​

uint64_t profiling_measurement_cycles = 1024;

variable partition_solver​

PartitionSolverType partition_solver = PartitionSolverType::Weighted;

variable num_threads​

size_t num_threads = std::thread::hardware_concurrency();

variable max_lookahead_cycles​

uint32_t max_lookahead_cycles = 100;

variable epoch_size​

uint64_t epoch_size = 64;

Cycles per epoch before sync.

variable enable_weighted_partitioning​

bool enable_weighted_partitioning = true;

variable enable_parallel​

bool enable_parallel = true;

Scheduler selection:

  • !enable_parallel → Sequential (single-thread)
  • enable_parallel && !enable_lookahead → Barrier (per-cycle sync)
  • enable_parallel && enable_lookahead → Lookahead (per-cluster atomics)

variable enable_lookahead​

bool enable_lookahead = true;

variable enable_dynamic_rebalance​

bool enable_dynamic_rebalance = true;

variable deterministic_partitioning​

bool deterministic_partitioning = false;

Skip live wall-clock profiling and partition units with constant unit_cost=1.0 + sync_cost=100ns. The partitioner's LPT becomes a pure round-robin and the resulting cluster_to_thread mapping is bit-exactly reproducible run-to-run (and often across num_workers for cost-insensitive topologies). Use for regression tests and A/B comparisons; leave off for production throughput.

variable cost_profile_cache_path​

std::string cost_profile_cache_path;

When non-empty, serialize the TickCostProfiler output here after the first profiling run and reuse it on subsequent runs whose topology hash matches. Cache hits skip the rdtsc profiler, removing measurement noise from run-to-run partitioning.

Updated on 2026-05-26 at 05:42:32 +0000