[marsavicc]

Motivation

Closes #13487
Closes #13631

On Windows gfx120X, the hipthreads lit tests and the examples hang in TheRock CI. All lit tests that run through hip::wthread time out, and saxpy hits the 30-minute job timeout. The same nightly passes on Windows gfx103X/gfx110X/gfx1151 and on Linux gfx120X.

Technical Details

threading_main is a persistent kernel. It keeps polling cpuWorkQueue.pushCount and exits once the host replaces the -1U value with the final push count. The host wrote that value with hipMemcpyToSymbolAsync. On Windows gfx12, the running kernel never sees it, even after the copy completes. So the kernel never exits, and the next null-stream operation (thrust::copy, hipDeviceSynchronize) waits on it forever.

hipMemcpyToSymbolAsync vs hipStreamWriteValue32:

• hipMemcpyToSymbolAsync is a data transfer. HIP only guarantees its result is visible to work that runs after it in the stream. A kernel that is already running is not guaranteed to see it.
• hipStreamWriteValue32 is a stream memory operation meant for signaling work that is already running. It is a single, ordered, aligned 32-bit write.

hipThreads already uses this approach for the work queue: sendToGPU publishes entries with hipStreamWriteValue64 because of a similar Navi4 issue. This PR does the same for pushCount.

Changes in src/hip/thread.cxx:

• notifyDeviceThereMightNotBeAnyMoreWork and the -1U re-arm in prepDeviceForWork now write pushCount with hipStreamWriteValue32, on the same enqueuing stream as before. The device address is cached.
• The notify path synchronizes the enqueuing stream so the write is submitted on Windows. This only waits on the enqueuing stream, not on mainStream.
• The static copy buffer is removed, since the value is now passed directly.

Test Plan

Windows 11, RX 9070 XT (gfx1201), TheRock nightly 10.2.0a20261012:

• lit (lit -j 1 test/)
• saxpy step3
• InOneWeekendRaytracer step4

Test Result

	Before	After
lit	35 timeouts	89 passed, 0 failed
saxpy	hang	pass
InOneWeekendRaytracer	hang	pass

🤖 Generated with Claude Code

[therock-pr-bot]

✅ All Checks Passed — Ready for Review

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[therock-pr-bot]

🎉 All checks passed! This PR is ready for review.

[marsavicc]

CI run on gfx1201 with the fix: https://github.com/ROCm/rocm-libraries/actions/runs/38381871451/job/115314385968

[DanielMcIntosh]

Approving this to get the CI green since it seems like it will solve the problem, but I have left some comments that should be addressed in a follow-up PR

[DanielMcIntosh]

LGTM

[assistant-librarian]

TheRock Submodule Bump Activity

Newest first

• 2026-10-30 — Included in TheRock via ROCm/TheRock#9626.