Fix cudaErrorHostMemoryNotRegistered: Memory Not Pinned

Overview

cudaErrorHostMemoryNotRegistered occurs when calling cudaHostUnregister on non-registered memory.

Error Messages

CUDA error: host memory not registered
cudaErrorHostMemoryNotRegistered

Common Causes

• •Unregistering non-registered memory
• •Memory already unregistered
• •Wrong pointer

Solutions

if (isRegistered(ptr)) {
    cudaHostUnregister(ptr);
    markUnregistered(ptr);
}

Prevention Tips

• ✓Track registration state
• ✓Pair register/unregister calls

Code Examples

Before (Problematic)

Must register first.

cudaHostUnregister(ptr);  // Never registered

After (Fixed)

Paired calls.

cudaHostRegister(ptr, size, 0);
// ... use ...
cudaHostUnregister(ptr);

Frequently Asked Questions

Related Errors

Need help debugging CUDA errors? Download RightNow AI for intelligent error analysis and optimization suggestions.