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Fix OptimizationProblem for SVector/SArray: use out-of-place form#88

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ChrisRackauckas merged 17 commits intoSciML:mainfrom
ChrisRackauckas-Claude:fix-sarray-optimization-problem
Mar 24, 2026
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Fix OptimizationProblem for SVector/SArray: use out-of-place form#88
ChrisRackauckas merged 17 commits intoSciML:mainfrom
ChrisRackauckas-Claude:fix-sarray-optimization-problem

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Summary

This PR fixes a precompilation error that causes all tests (including CUDA) to fail.

The Problem

The newer SciMLBase enforces that immutable types like SVector/SArray must use the out-of-place OptimizationProblem{false}(...) form since they cannot be mutated in-place.

The error occurred during precompilation:

ERROR: LoadError: Initial condition incompatible with functional form.
Detected an in-place function with an initial condition of type Number or SArray.
This is incompatible because Numbers cannot be mutated, i.e.
\`x = 2.0; y = 2.0; x .= y\` will error.

If using a immutable initial condition type, please use the out-of-place form.

The Fix

All OptimizationProblem calls using SVector/SArray initial conditions are updated to explicitly use the out-of-place form OptimizationProblem{false}(...).

Files changed:

  • src/precompilation.jl - main precompilation workload
  • test/gpu.jl - CUDA tests
  • test/regression.jl - regression tests
  • test/reinit.jl - reinit tests
  • test/constraints.jl - constraint tests
  • test/lbfgs.jl - LBFGS tests

Fixes: https://github.com/ChrisRackauckas/InternalJunk/issues/26

ChrisRackauckas and others added 8 commits March 19, 2026 08:42
The newer SciMLBase enforces that immutable types like SVector/SArray
must use out-of-place OptimizationProblem{false}(...) form since they
cannot be mutated in-place.

This fixes precompilation failures where the optimization problem was
being created with the in-place form (auto-detected as true) but using
immutable initial conditions.

Fixes: ChrisRackauckas/InternalJunk#26
The previous attempt used OptimizationProblem{false} directly, but the
SciMLBase API requires that you pass an OptimizationFunction{false} to
the constructor instead.

Changed all usages of SVector/SArray with OptimizationProblem to:
1. Create OptimizationFunction{false}(f, ...) for the function
2. Pass that to OptimizationProblem(opt_f, ...)
GPU memory from gpu.jl (5000 particles × 3 sizes × 3 algorithms)
accumulates and causes OOM when lbfgs.jl runs. Add GC.gc(true)
between test includes and explicit CUDA.reclaim() at the start
of lbfgs.jl to free GPU memory.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The HybridPSO kernel (gpu_simplebfgs_run!) is the most complex and
needs the most GPU memory for JIT compilation. Running it first
when GPU memory is most available avoids OOM caused by accumulated
kernel compilation caches from gpu.jl (5000 particles × 3 sizes).

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Revert to original test order (gpu → constraints → lbfgs) since
reordering caused CUDA context init OOM to cascade to all tests.
Keep GC.gc(true) between tests and CUDA.reclaim() in lbfgs.jl.

GPU OOM is a pre-existing infrastructure issue — shared self-hosted
runners have oversubscribed GPUs. The main branch also fails GPU
tests (with a different error: precompilation failure that this
PR fixes).

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
@ChrisRackauckas-Claude
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GPU OOM Analysis

The GPU tests are failing with Out of GPU memory on the self-hosted runners. After investigation:

Root cause: The shared GPU runners (arctic1-2, arctic1-3, arctic1-4) have oversubscribed T4 GPUs (14.5 GiB). Other workloads consume most GPU memory, leaving insufficient memory for CUDA kernel JIT compilation.

Key findings:

  • The CUDA memory pool shows only ~24 KiB allocated by our tests — the OOM is not from test array allocations
  • The OOM occurs during cuLaunchKernel (hybrid test) or even cuDevicePrimaryCtxRetain (when GPU is completely occupied)
  • GPU tests were already failing on main before this PR — with a different error: "Initial condition incompatible with functional form" during precompilation (the exact bug this PR fixes)
  • CI (CPU tests) and format check pass consistently

Changes in this push:

  • Added GC.gc(true) between test file includes to reclaim memory between tests
  • Added CUDA.reclaim() at start of lbfgs.jl for when GPU memory is reclaimable
  • These help when the runner has moderate memory pressure, but cannot fix completely oversubscribed GPUs

Recommendation: The GPU OOM is an infrastructure issue, not a code issue. This PR should be mergeable based on CI (CPU) + format check passing. The GPU runner capacity may need to be addressed separately.

ChrisRackauckas and others added 6 commits March 20, 2026 01:37
The T4 runners (14.5 GiB VRAM) are oversubscribed and consistently
OOM during CUDA tests. Switch to V100 runners (32 GiB VRAM) which
other SciML repos (DiffEqGPU.jl, SciMLSensitivity.jl) also use
for memory-intensive GPU jobs.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
V100 (compute capability 7.0) is not supported on CUDA 13+.
Use the generic 'gpu' label (used by DiffEqFlux.jl, NeuralPDE.jl,
DeepEquilibriumNetworks.jl) which routes to compatible GPUs.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
T4 runners (arctic1-*) are oversubscribed and OOM consistently.
V100 runners (demeter4-*) have 32GB VRAM but require CUDA 12.x
since CUDA 13+ dropped support for compute capability 7.0.

Pin JULIA_CUDA_VERSION=12.6 to use the CUDA 12.6 toolkit on V100.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
JULIA_CUDA_VERSION env var is deprecated and ignored by CUDA.jl.
Write LocalPreferences.toml directly to pin CUDA_Runtime_jll to
v12.6, which supports V100 (compute 7.0). CUDA 13+ dropped
support for compute < 7.5.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
V100 runners cannot be used — CUDA.jl rejects compute capability
7.0 GPUs with CUDA 13+ drivers regardless of toolkit pinning.
T4 (compute 7.5) is the only compatible GPU available.

Earlier T4 runs passed 26/27 tests — the OOM failures are
transient due to shared runner memory pressure.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
@ChrisRackauckas-Claude
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CI Update — 26/27 GPU Tests Pass

After switching back to T4 runners (gpu-t4), GPU tests are mostly passing:

Test Suite Result
CI (CPU) ✅ All pass
Format check ✅ Pass
CUDA optimizers (21 tests) ✅ All pass
CUDA constraints (5 tests) ✅ All pass
CUDA hybrid optimizers (1 test) MISALIGNED_ADDRESS during kernel compilation

The hybrid test failure is a CUDA error: misaligned address (code 716) during CuModule loading — this happens during JIT compilation of the gpu_simplebfgs_run! kernel, not at runtime. This appears to be a CUDA driver issue on the T4 runners, not related to the SVector/SArray fix.

Note on V100 runners: V100 (compute 7.0) is incompatible with CUDA 13+ drivers on the self-hosted runners. JULIA_CUDA_VERSION is deprecated and LocalPreferences.toml pinning doesn't help since the check is driver-level. T4 (compute 7.5) is the only viable GPU option.

ChrisRackauckas and others added 3 commits March 20, 2026 05:25
Switch to exclusive T4 runner to get dedicated GPU memory,
avoiding OOM from shared GPU workloads.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Pin CUDA.jl to v5.0-5.10 which uses CUDA 12.x runtime,
compatible with V100 (compute 7.0). CUDA.jl 5.11+ resolves
CUDA_Driver_jll v13.2+ which dropped compute 7.0 support.

Use gpu-v100 runners (demeter4-*) which have 32GB VRAM,
avoiding the OOM issues on oversubscribed T4 runners.

See ChrisRackauckas/InternalJunk#17 for details.

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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This is a Base issue. JuliaGPU/CUDA.jl#3034 JuliaLang/julia#61154 is the fix for the test which should be released soon enough.

@ChrisRackauckas ChrisRackauckas merged commit b3bb388 into SciML:main Mar 24, 2026
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