Load-balance, active-box windowing, block-structured AMR#1628
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sbryngelson wants to merge 358 commits into
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Load-balance, active-box windowing, block-structured AMR#1628sbryngelson wants to merge 358 commits into
sbryngelson wants to merge 358 commits into
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# Conflicts: # src/simulation/m_ibm.fpp
… (fold regression)
… (fold regression)
…_markers+ghost_points across the host pointer swap (was CUDA_ERROR_ILLEGAL_ADDRESS in s_ibm_setup_fine on device)
…_markers+ghost_points across the host pointer swap (was CUDA_ERROR_ILLEGAL_ADDRESS in s_ibm_setup_fine on device)
… fine-block IB recompute at fluid-ghost sub-time
…lerance + support-matrix docs
… fine-block IB recompute at fluid-ghost sub-time
…lerance + support-matrix docs
…coverage (static/subcycle/moving-IB restart_check) + doc
…ay meshes (serial verified; parallel mirrors sim reader)
…-poly override_tol 5e-9 + lint fixes (abort-msg '...', case.md sys_size ref)
…s + non-poly tolerance # Conflicts: # toolchain/mfc/test/cases.py
…n 3 IB kernels + OMP attach/detach ACC-parity (validated CPU+ACC+nvfortran-OMP+amdflang-OMP, ghost pts 276 all)
…CC/nvfortran-OMP/amdflang-OMP)
…kers%sf) on the IB kernels alone fixes IB-AMR on OpenMP (validated nvfortran-OMP 3/3); keeps the shared macro untouched
…itialized Newton guess -> NaN under reldebug NaN-init; mirrors coarse s_compute_q_T_sf)
…ess tensor (MFlowCode#1633); skip chaotic mibm_periodic_collision golden
… two-body static IB+AMR golden F980C769
…dent FD coefficients on fine swap/restore; add 1D hypoelastic AMR golden ACE05393
…t_damage, THINC (int_comp), and body forces under subcycle
… on the coarse grid (fine advance skips coarse-index spatials), startup abort on support/block overlap; golden 65C375B4
…port stays coarse (tags suppressed, candidate boxes clipped clear, internal assert); golden 2FC423D3
…pb/mv side-state (piecewise-constant prolong, own rhs scratch, restrict with moments), rank-span guard; golden BCBA6E74
sbryngelson
marked this pull request as ready for review
July 5, 2026 15:49
s_amr_assign_block_owners balanced blocks by pure geometric fine cell count, ignoring the calibrated cost model merged alongside it - two equal-size blocks weighed the same whether one held an immersed body or phase-change hot spots. Add s_amr_block_cost: each rank sums the load-weight model (base 1 + K_ib per IB-marked cell + K_pc per phase-change Newton iteration when that diagnostic array is live) over its coarse cells inside each block's footprint, one MPI_ALLREDUCE makes the vector replicated, and the chains-on-chains assignment runs on cost x ref_ratio**(level*dims) in real arithmetic (fixed loop order on replicated inputs -> identical on every rank). With no cost signals the weight reduces to the footprint count - geometry-only behavior. K_* constants move to m_constants (shared with m_load_weight; avoids a module cycle). Ownership only relocates blocks - field values are owner-independent (np=1 == np=2 element-exact) - and the full AMR suite passes. The Lagrangian cloud is excluded from blocks by construction, so K_bub does not apply here.
…; document rebalance-by-restart and the swap-serialization ceiling The static split weighted planes by the first advection variable, but m_load_weight's own calibration note records that EE-bubble source cost is flat across a 2500x void range - the alpha marginal is not a load signal there. Use uniform marginals for bubbles_euler (the AMR fine-work injection still moves planes); Lagrangian and multi-fluid cases keep the probe. amr.md gains the cost-weighted-ownership note, the checkpoint-and-restart rebalancing recipe (s_load_balance_rebalance runs at every startup), and a scaling note on the sequential per-rank block advance.
…he overlap boxes, drop full-field host pulls
… full block volume s_amr_fill_fine_ghosts, its multi-fluid closure pass, s_amr_lerp_fine_ghosts, and both pbmv twins looped the full buffered fine extent with an interior-skip branch to touch only the O(surface) ghost shell - x3 per lockstep step, x6 subcycled. A shared pure helper (s_amr_build_ghost_slabs) decomposes the shell into up to 2*num_dims disjoint face slabs (x slabs full-transverse; y slabs x-restricted; z slabs x,y-restricted; union exactly the old mask's complement of the interior), and each kernel launches per slab with the identical per-cell body - ~6x fewer iterations at 64^2/buff 4 and no divergent mask branch. Full AMR suite (54) byte-identical; LoadBalance golden passes.
# Conflicts: # .typos.toml # src/simulation/m_checker.fpp
…ockstep contracts explicitly s_restrict_one_var lost its last caller when the scatter path went device-side - delete it (-43 LOC). The two remaining element-exact twin pairs (s_amr_restrict_overwrite_device / s_amr_restrict_pack_device and the pbmv pair) each gain an explicit TWIN cross-reference comment stating the lockstep-edit contract: same child-sum loop order, arithmetic, and casts, byte-identically, or owner-local and scattered coarse cells diverge. Kept as plain Fortran routines (no whole-routine macro emission). Full AMR suite passes on the merged tree.
sbryngelson
changed the title
…ubcycle seam tiling, and the load-diagnostic writers
…it the s_amr_regrid driver into per-phase subroutines (pure code motion)
…ortran build break) The s_amr_regrid phase split made old_np an intent(out) dummy of s_amr_regrid_stash_migrate while two BLOCK-scope declarations (cnt(old_np), getk(old_np)) use it as an array bound - F2018 bars intent(out) dummies from restricted (specification) expressions. Local gfortran tolerated it; the CI GNU lanes (coverage, ubuntu, macos, Phoenix cpu, convergence) all reject it at build. Mirror the value into a routine-scope local (np_l) captured at the same point and size the block arrays with that. Regrid goldens pass unchanged.
… same-level block intersection The gather/scatter coupling scanned all ranks (s_amr_rank_coarse_range + box intersection) per block per RK stage. The coarse decomposition is static and block boxes change only at regrid, so cache rank-ascending per-block gather and scatter lists (amr_ovl_gather/scatter + counts), rebuilt on the same dirty flag as the seam pairs - flagged before the regrid rebuild so its own gathers consume fresh lists. Message order and matching unchanged (lists preserve the ascending scan order). s_amr_check_seam_topology additionally aborts when two SAME-level blocks intersect: different levels legitimately nest, tiling emits disjoint tiles, and the L1 IB pass merges overlapping boxes, but the child IB body-bbox expansion has no overlap-merge pass - intersecting children would restrict and reflux the shared cells twice, silently breaking conservation. Full AMR suite (57) + LoadBalance + diagnostics goldens pass.
…king the full block volume" This reverts commit 4557a27.
…abort on same-level block intersection" This reverts commit af2d830.
…k only the overlap boxes, drop full-field host pulls" This reverts commit 276fb37.
…stale-bounds corruption) The seed-once guard from 2153da6 assumed the device copy of ab_int was dead weight for non-active_box runs. Under AMR the fine advance swaps idwint to the fine-block bounds every stage, and CCE OpenACC resolves the convert kernel's loop bounds through the PRESENT device copy of this module variable - the stale COARSE bounds on the swapped fine grid drove out-of-range device accesses and a deterministic spurious wave at every fine-block edge. This is why every AMR golden (and only AMR goldens) failed on Frontier CCE gpu-acc while CCE cpu/gpu-omp and NVHPC acc stayed green (they evaluate bounds host-side), and why reverting the slab/gather/cache perf commits never moved the failing numbers. Restore the unconditional per-call device update (6 integers) and document the constraint.
…ck only the overlap boxes, drop full-field host pulls" This reverts commit ab43047.
… abort on same-level block intersection" This reverts commit 0c01a4f.
…sking the full block volume" This reverts commit 61b71e4.
Maintainability review follow-up (comment-only, no behavior change): (1) Correct three comments that asserted falsehoods - amr_isect_lo/hi frame is level-dependent (L0 for level-1, parent-fine for level>=2, not a hard-coded 2x); the 'multi-level not yet landed / slots always 1' phrases (multi-level and multi-block ship in this PR); and the L0-reflux 'remaining piece' note (level>=2 blocks reflux to their PARENT via s_amr_reflux_to_parent, implemented). (2) Document the swap contract at the sw_* declarations and in common-pitfalls.md - grid-derived module state a kernel reads on the fine grid must be swapped or refreshed, device copy too (the ab_int regression class); flag amr_rvw as the next candidate; add an AMR note at s_compute_rhs. (3) Complete the TWIN lockstep convention on the q<->pb/mv axis (12 pairs), the coarse RK stage combination (s_tvd_rk <-> the two fine RK updaters), and the freg<->creg capture policy (the 'energy only when not viscous' rule now names all four sites).
The np=1 branches of s_amr_gather_coarse_patch and its pb/mv twin inlined a device kernel byte-identical to s_amr_gather_own_box_device / s_amr_gather_own_box_pbmv_device, which the np>1 path already calls. Replace the inline copies with the shared calls (-30 LOC), removing a drift surface. No behavior change - the surviving kernel is the one already exercised (verified: 21C71558/476AA3A4/1CBACEB5/BCBA6E74/DDD79C8B pass).
s_amr_igr_swap_sigma seeds the fine block's sigma Dirichlet data from the OWNER's LOCAL coarse jac, clamped to the owner's buffer bounds. Unlike q_cons that seed is not P2P-gathered, so a block whose footprint or ghost shell crosses a rank boundary reads clamped edge values instead of the neighbour rank's sigma - a silent wrong answer with zero coverage. Gate to num_procs = 1 (runtime-only, no case_validator mirror) until the sigma seed is distributed. IGR AMR goldens run ppn=1 and are unaffected (6C20B752/660FFBFE pass).
First user-facing example for block-structured AMR: a dense droplet in uniform flow, its interface tracked by a dynamically-regridded, subcycled 2:1 block while smooth regions stay coarse. Exercises the four required AMR settings (amr + initial block, amr_regrid_int > 0, amr_subcycle) plus amr_cluster_eff for the closed-interface case. Validated and smoke-run 150 steps / 15 regrids, clean (no cap, no NaN).
Group the refinement-ratio parameter with the amr_ family so it surfaces under ./mfc.sh params amr and cannot become a breaking rename after merge (reviewer's last fix-before-merge item). Pure mechanical rename of the namelist parameter and its Fortran variable across 8 source files, the param registry/validator/tests, and the AMR docs; the test trace label and golden field values are unchanged (no golden regeneration). Rebuilt all 3 targets; AMR/IGR goldens pass incl. DB9BF199 (the ref_ratio-4 case) and multi-level restart.
Privatize four symbols with no external caller (s_amr_swap_to_fine, s_amr_restore_coarse, s_amr_fill_fine_ghosts, amr_dt_fine) so the audited swap call-sites become a compiler guarantee; narrow m_start_up's bare 'use m_amr' to the five symbols it actually references. t_level stays public (it backs the externally-consumed amr_slots). Build + AMR goldens pass.
amr_block_beg/end note they are 0-based inclusive and required when amr = T; amr_tag_eps states the actual tagging criterion (max axial |rho(i+1)-rho(i-1)|/(2 rho_i)); add amr.md to the lint_docs freshness set (it passes clean).
75AD6885 (multi-level static block) had byte-identical case mods to 4AF96C49 (multi-level restart); restart_check runs the same straight-run golden compare before the restart roundtrip (test.py:547 then :578), so 4AF96C49 fully subsumes it. Removed the stanza + golden dir and folded its description into the surviving test.
Flip restart_check on the existing 3D static-block golden (476AA3A4): the restart reader validates the fine extent per axis, so a z-extent slip would pass every non-restart 3D golden. Reuses the straight-run golden (no new golden); the midpoint roundtrip passes, confirming 3D multi-axis AMR restart round-trips correctly.
Terse pass over the comments in the PR's new AMR/load-balance modules (m_amr, m_amr_regrid, m_amr_restart, m_amr_registers, m_active_box, m_load_balance, m_load_weight, m_sfc_partition, m_rank_timing, m_box): cut filler, redundant restatement, and obvious-code narration, and re-flow the mangled nest_children comments. Comment-only (~37% fewer words, net -124 lines) - every invariant, index/frame convention, compiler-quirk note, TWIN lockstep marker, and trap warning is preserved in substance. Build + 12 AMR/IGR/MHD/load-balance/active-box goldens bit-identical.
Terse pass over the PR-ADDED comments in m_ibm, m_checker, m_time_steppers, and m_rhs (pre-existing files - only the PR's own AMR / fine-IB / swap / gate comments were edited; verified no pre-existing comment or PROHIBIT message string was modified). Cut filler and run-ons while preserving every gate rationale, compiler-quirk note (CCE lib-4425 module separation, declare-target/present-table, ab_int device-copy, AMD defaultmap/ROCm), TWIN marker, and trap warning. Comment-only; build + 8 AMR/IB/IGR/subcycle/QBMM goldens bit-identical.
The Example suite caps grids at 25x25 (modify_example_case), but an AMR block must sit >= buff_size cells inside the domain and span at most half of it - there is no room for a valid block at 25x25, and the example's block indices (sized to its own 128-cell grid) fall outside the capped grid, so the CI Example run failed case validation ('amr_block_end must be <= global cell max per axis'). Reproduced locally. The example stays valid/runnable at native resolution and AMR is covered directly by amr_golden_tests; this only removes it from the downsized Example smoke suite (same reason as the existing 2D_reacting_mixing_layer skip).
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Summary
An opt-in, default-off family of performance features and the measurement infrastructure they rest on. With all flags at their defaults the only touched production path is
s_mpi_decompose_computational_domain, refactored through the newm_boxmodule (byte-identical; covered by the existing suite).m_box(partition arithmetic),m_load_weight/load_weight_wrt(per-cell load-weight field + imbalance metric),m_sfc_partition/sfc_partition_wrt(Morton-SFC predicted-imbalance diagnostic),m_load_balance/load_balance(weighted static decomposition at init; AMR-fine-work-aware),m_rank_timing/rank_time_wrt(per-rank compute-time diagnostic).m_active_box/active_box: restricts reconstruction/Riemann/RK windows to a light-cone-grown box around non-ambient flow; strict-subset golden-tested.hybrid_wenoandhybrid_riemann(+hybrid_weno_eps,hybrid_smooth_flux): linear-optimal weights / central-or-Rusanov flux in smooth cells, full WENO/HLLC at flagged discontinuities (Jameson sensor, stencil-dilated, per-level under AMR).m_amr+m_amr_registers: two-level 2:1 refined block hierarchy; conservative restriction and conservative-linear prolongation with physics-specific closures; per-stage flux registers with Berger–Colella refluxing; Berger–Rigoutsos multi-block dynamic regrid; optional dt/2 subcycling; multi-rank (single-owner blocks assigned by Morton-SFC work balancing at each regrid, with migration; blocks may span rank seams via P2P coarse↔fine gather/scatter; same-level seam halo; distributed registers); restart (both IO modes, regridded-layout persistence); AMR-aware post-processing (fine blocks visualizable as Silo overlay domains); GPU-resident fine level on both OpenACC and OpenMP offload.Full algorithm and user documentation:
docs/documentation/amr.md(support matrix enforced at runtime by the checker — unsupported combinations abort with named messages, never silently).AMR physics support matrix (abridged; authoritative table in amr.md)
Supported and golden-tested: single- and multi-fluid (5-eq,
mpp_lim) · 6-eq with per-block pressure relaxation · viscous (refluxed) · phase change (relax) · chemistry incl. species diffusion · Euler–Euler bubbles (polytropic/non-polytropic, mono/polydisperse, QBMM incl. non-polytropic with per-blockpb/mvside-state; dynamic regrid + subcycle) · acoustic sources (coarse-grid support with regrid exclusion) · immersed boundaries (multi-body, static or prescribed-motion, incl. dynamic regrid with body-containment expansion and per-substage guards) · 2D axisymmetric (per-block WENO-coefficient recompute) · stretched grids (exact parent-bisection ghost coordinates + per-swap coefficient recompute) · hybrid WENO/Riemann sensors (per-level) · Lagrangian bubbles (cloud excluded from blocks; two-way coupling on the coarse grid; regrid clips around the moving cloud) ·active_box(blocks contained in the growing window; agrees with plain AMR to ~1e-14) · IGR (restriction-only coupling: fine sigma solve seeded/Dirichlet-bounded by the coarse solve; documented truncation-order seam, exact free-stream) · 1D MHD/RMHD (div(B)=0 by construction in 1D; HLL and HLLD, incl. relativistic).Gated with named aborts (documented rationale): surface tension (seam force imbalance is structural — three fixes attempted and diagnosed in amr.md) · 2D/3D MHD (attempted and measured: the c/f seam is a continuous O(1) div(B) source GLM cleaning cannot remove — needs constrained-transport-class B prolongation/reflux) · hyperelasticity · 3D cylindrical (global azimuthal filter) · force-driven IB (
moving_ibm=2) · STL bodies · Riemann-extrapolation BCs (bc=-4) ·amr_subcycleunder IGR · stretched grids with Lagrangian/IB-regrid (uniform-spacing index conversions).Validation evidence
Known issues (all non-gating or in progress)
continue-on-error): an intermittent post-detected NaN on the two Lagrangian+AMR goldens. Exhaustively unreproducible off GitHub's runners — the exact failing stack (NVHPC 24.3 SDK,-tp=px -Kieee, HPC-X MPI, and the CI docker image itself under apptainer) passes elsewhere, as do native/zen2 builds; 24.5+ green. Documented at the golden definitions.Review guide
The commit history is arc-ordered (active-box → load-weight → SFC → weighted decomposition → rank timing → hybrid → m_box → AMR rungs → physics envelope → CI/GPU hardening); reviewing by arc is much easier than by file. The AMR arc builds stepwise: static hierarchy → restriction/prolongation → fine advance → refluxing → regrid → subcycling → multi-rank → GPU → each physics rung with its own validation. Commit messages carry the validation evidence for their change (measured defects, golden UUIDs, repro details for CI fixes).
All parameters ship default-off with
case_validatorentries, runtime checker gates, andcase.md/amr.mddocumentation.