[iassiour]

hipHostMalloc does not guarantee zeroed memory. The host competitor buffer
in the *_Host_And_GPU atomics tests was used uninitialized.

Motivation

The atomicAdd/Sub/CAS_system_Positive_Host_And_GPU tests allocate the
host competitor buffer with hipHostMalloc and immediately run host
__atomic_fetch_add on it — without initializing to zero. The device
buffers are hipMemset'd, but the host buffer is not. Since hipHostMalloc
does not guarantee zeroed memory (same as malloc), the test accumulates
onto undefined contents and fails the final comparison.

Technical Details

One-line fix in arithmetic_common.hh TestCore(): add
std::memset(host_ptr, 0, size) after hipHostMalloc, before host
threads run. Uses host-side memset (not hipMemset) since the buffer
is only touched by host threads.

Issue Tracking

JIRA ID : ROCM-28378

Test Plan

Ran all affected tests: atomicAdd_system_Positive_Host_And_GPU (6 type
sections), atomicSub_system_Positive_Host_And_GPU,
atomicCAS_system_Positive_Host_And_GPU (4 type variants) — all pass.
Tests using other common headers (atomicExch, And/Or/Xor, Min/Max) are
not affected.

Test Result

All pass. No regressions.

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/rocm-systems/blob/develop/CONTRIBUTING.md.

[therock-pr-bot]

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[Copilot]

Pull request overview

This PR fixes nondeterministic failures in HIP atomics “*_Host_And_GPU” tests by ensuring the host-side competitor buffer allocated via hipHostMalloc is explicitly zero-initialized before any host atomic operations run.

Changes:

• Add <cstring> include to support std::memset.
• Zero-initialize the hipHostMalloc host competitor buffer in TestCore() before launching host threads.

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[github-actions]

This pull request has been inactive for 25 days and will be marked as stale.

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[github-actions]

This pull request has been automatically closed due to inactivity (30 days with no updates).

If you'd like to continue working on this, feel free to reopen the PR or create a new one.

[mangupta]

🤖 AI-assisted pre-review (for @mangupta)

Re-reviewed the updated head (a179f34a9728) — no new findings at or above the posting threshold.

[Copilot]

🟢 Approval recommended

The initialization correctly addresses the uninitialized-memory failure without introducing unresolved issues.

0 open findings

🧠 Review effort: Balanced

[systems-assistant]

TheRock Submodule Bump Activity

Newest first

• 2026-10-15 — Included in TheRock via ROCm/TheRock#9003.