udp.pcbcount leak

my case:

The phenomenon you're describing, where the "net.inet.udp.pcbcount" value significantly increases after closing the lid of a MacBook Pro and waiting for a while before reopening it, can indeed be indicative of a UDP (User Datagram Protocol) PCB (Protocol Control Block) leak. PCBs are data structures used by the operating system to manage network connections.

When a UDP connection is established, a PCB is created to store information about that connection. However, if the PCB is not properly released or closed when the connection is terminated, it can lead to a resource leak. In this case, it appears that the number of UDP PCBs keeps increasing every time you close and reopen the lid of your MacBook Pro.

The increasing number of UDP PCBs can lead to higher CPU usage and increased CPU temperature because the system needs to maintain and manage all these active connections. As the number of PCBs continues to rise, it consumes more system resources and can impact overall performance.

To address this issue, you can try the following steps:

Check for software updates: Make sure your MacBook Pro is running the latest version of macOS and has all the latest updates installed. Apple often releases software updates to address known issues and bugs. Restart your MacBook Pro: A simple restart can help clear any temporary system glitches and potentially release any lingering UDP PCBs. Reset network settings: Go to "System Preferences" > "Network" and select your network connection (Wi-Fi or Ethernet). Click on the "Advanced" button and then choose the "TCP/IP" tab. From there, click on the "Renew DHCP Lease" button and then "OK" to apply the changes. This will reset your network settings and may help resolve the issue. Check for rogue applications or processes: It's possible that a specific application or process is causing the UDP PCB leak. Monitor your system's activity using the "Activity Monitor" application (located in the "Utilities" folder within the "Applications" folder) and look for any processes or applications that may be consuming a large number of UDP PCBs. If you identify any suspicious processes, try updating or uninstalling the corresponding application. Contact Apple Support: If the issue persists and none of the above steps resolve the problem, it's recommended to reach out to Apple Support or visit an Apple Authorized Service Provider for further assistance. They can help diagnose the issue and provide specific troubleshooting steps or repair options. Remember to back up your important data regularly to ensure you don't lose any information in case further troubleshooting or repairs are required.

I hope this helps!

Using the methods you provided, except for restarting the machine, the issue did not improve. One of the great features of Mac is its excellent lid wake functionality, which allows for a seamless experience without the need to shut down the computer. If frequent restarts are required to reduce CPU overheating and restore performance, it would significantly impact the Mac user experience.

From my understanding, this problem is not uncommon (among the five people I know who use Mac, one of them also experiences this issue). However, the problem may not be easy to identify, as it requires individuals with a background in computer systems to dig deeper into the system mechanisms to discover some clues. Most ordinary Mac users may only notice severe CPU overheating or slower system performance.

In my opinion, it would be helpful if macOS developers could observe or address this issue at the operating system level. Here are some suggestions:

1. For example, provide a command that can monitor which process is consuming a significant number of UDP PCBs. Users can then uninstall or kill the identified process.
2. If a process exceeds a certain threshold of UDP PCB usage, automatically kill the process and record it in system logs, similar to the OOM (Out of Memory) mechanism in Linux.
3. If it is a bug in the macOS kernel, such as a bug in the PCB management mechanism triggered by an application, it is hoped that it can be fixed promptly.

This issue has been bothering me for several months, and I hope Apple can assist me in resolving it. I strongly prefer not to restart my macbook frequently. @HunterBD

Hello again!

I understand your frustration with the issue you're experiencing on your Mac and your desire for a solution that doesn't require frequent restarts. Perhaps I can provide some additional suggestions and information that might be helpful.

1. Check Activity Monitor: Launch the Activity Monitor utility (you can find it in the Utilities folder within the Applications folder) and select the "CPU" tab. Look for any processes that are consuming a significant amount of CPU resources. If you notice any particular process causing high CPU usage, you can investigate further or consider uninstalling that application.

2. Update macOS and Apps: Make sure you're running the latest version of macOS and that all your applications are up to date. Software updates often include bug fixes and performance improvements that could help resolve the issue you're experiencing.

3. Reset SMC and NVRAM: Resetting the System Management Controller (SMC) and NVRAM (non-volatile random-access memory) on your Mac can sometimes help with performance issues and overheating problems. Instructions for resetting the SMC and NVRAM can be found on Apple's support website or by searching online for your specific Mac model.

4. Check for Malware: Occasionally, malware or unwanted applications can cause high CPU usage and overheating. Consider running a thorough scan with reliable antivirus software to check for any malicious programs on your Mac.

5. Seek Apple Support: If the issue persists and you've exhausted all troubleshooting options, it may be beneficial to reach out to Apple Support directly. They have specialized knowledge and resources to assist with macOS-related issues and can provide specific guidance based on your situation.

Remember to provide detailed information about the problem, including any specific error messages, the steps you've already taken to troubleshoot, and the exact model and specifications of your Mac. This will help Apple Support better understand your situation and provide appropriate assistance.

While these suggestions may not directly address the underlying cause of the issue you're experiencing, they can help mitigate the problem until a more permanent solution is found.

Please let me know if these comments prove helpful.