fix Fuzz constant OOM for CUDA

[a10y]

Summary

The Fuzz check has been failing for CUDA compress_gpu job for a very long time now (at least a month).

After some investigation, it appears this is because ASAN will mprotect a very large memory region that conflicts with some address space that the CUDA driver wants to own, resulting in cudaCtx initialization failing with OOMs like we've been seeing.

I've run a sample Fuzz workflow with this change and confirmed we are able to get past context init now.

[a10y]

First run: https://github.com/vortex-data/vortex/actions/runs/27706306865

Actual first run: https://github.com/vortex-data/vortex/actions/runs/27706466820/job/81956199153

Working run: https://github.com/vortex-data/vortex/actions/runs/27710006987/job/81992356488#step:5:186

[codspeed-hq]

Merging this PR will improve performance by 15.58%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 7 improved benchmarks
❌ 1 regressed benchmark
✅ 1573 untouched benchmarks
⏩ 11 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Simulation	chunked_varbinview_into_canonical[(1000, 10)]	177.7 µs	213.9 µs	-16.94%
⚡	Simulation	take_10k_random	255.8 µs	197.8 µs	+29.27%
⚡	Simulation	take_10k_contiguous	276.3 µs	218.5 µs	+26.46%
⚡	Simulation	patched_take_10k_contiguous_patches	291 µs	232.3 µs	+25.26%
⚡	Simulation	patched_take_10k_random	303 µs	244.2 µs	+24.07%
⚡	WallTime	cuda/bitpacked_u8/unpack/3bw[100M]	352 µs	301.7 µs	+16.69%
⚡	Simulation	bitwise_not_vortex_buffer_mut[128]	215.3 ns	186.1 ns	+15.67%
⚡	Simulation	bitwise_not_vortex_buffer_mut[1024]	275.6 ns	246.4 ns	+11.84%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing aduffy/debug-cuda-fuzz-oom (18787a8) with develop (85aad72)}

Footnotes

1. 11 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[0ax1]

Happy when CI is happy 🙂