Fix cudaErrorPeerAccessNotEnabled: P2P Not Active

Overview

cudaErrorPeerAccessNotEnabled occurs when disabling P2P access that was never enabled or already disabled.

Error Messages

CUDA error: peer access not enabled
cudaErrorPeerAccessNotEnabled

Common Causes

• •Disabling P2P without enabling first
• •Double disable
• •P2P enable failed silently

Solutions

cudaDeviceEnablePeerAccess(peerDev, 0);
// ... use P2P ...
cudaDeviceDisablePeerAccess(peerDev);

cudaError_t err = cudaDeviceEnablePeerAccess(dev, 0);
if (err == cudaSuccess) {
    p2pEnabled = true;
}

Prevention Tips

• ✓Track P2P state
• ✓Check return values

Code Examples

Before (Problematic)

Disabling without enabling.

cudaDeviceDisablePeerAccess(1);  // Never enabled!

After (Fixed)

Track state properly.

if (p2pEnabled) {
    cudaDeviceDisablePeerAccess(1);
    p2pEnabled = false;
}

Frequently Asked Questions

Related Errors

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