![]() In multi-processor aware programs, individual threads are used to send tasks to available processor cores. ![]() These sub-processes are called threads, and can make applications run more efficiently, depending on the hardware they are running on. It can be compared with the %CPU number to see if the process regularly takes up a lot of the CPU, or if any observed spikes in the %CPU statistic are just temporary.Īpplications can be programmed to be multithreaded, which means separate tasks can be divided up into their own sub-processes that each run independently and in parallel with each other. This is a running tally of the amount of time the CPU has spent on running the process. When a process is programmed inefficiently, or has bugs in the code logic, the amount of CPU used can skyrocket and hog computing resources from other applications. This will only happen for processes that are multi-processor aware, and others will maximize at 100% but the system will divide their work among the various processors. This is the percentage of the overall processing power in the system being used by the process, and is relative to one CPU core, so many times in multiprocessor systems you will see a process take up 150% of the CPU, which indicates in a 2-core system that 75% of the total CPU power is being used by that process. There are ways to temporarily promote a user to "root" in order to manage other processes, but we will not discuss that here. The root user technically owns "everything" in the system, but system users by default can only directly control the subset of processes that they own. When the system boots up, the initial "launchd" process is started under the "root" user, and subsequent processes launched under this "launchd" umbrella are owned by this same user. This is the owner of the process, or the active user under which the process was started. The ones with abbreviated names such as "ntpd" or "hidd" are background processes that provide system support but for the most part aren't directly managed by the user. The process name is the common name for the application, such as "Mail", or "Finder". Every process is associated with its own Process ID, the Process ID of it's "parent" process, and the process group of which it is a member (generally the "parent" process). Progressively higher-level system processes are given PIDs up to approximately 200, with processes starting from user accounts being given higher process numbers. For instance, the kernel is given number 0, followed by 1 for the parent "launchd" process. Processes can technically be given any number that is not in use however, the system will use number ranges to separate different processes by levels of importance. You can help by adding a new language or improve the existing translation.Whenever processes are started in OS X, they are given a unique identifier number, which can be used to identify it for recognition by other commands (for example, the "kill" utility that terminates processes).
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