Performance
On a multi-core processor, native thread implementations can automatically assign work to multiple processors, whereas green thread implementations normally cannot. Green threads can be started much faster on some VMs. On uniprocessor computers, however, the most efficient model has not yet been clearly determined. Benchmarks on computers running the (ancient) Linux kernel version 2.2 have shown that:
- Green threads significantly outperform Linux native threads on thread activation and synchronization.
- Linux native threads have slightly better performance on I/O and context switching operations.
When a green thread executes a blocking system call, not only is that thread blocked, but all of the threads within the process are blocked. To avoid that problem, green threads must use asynchronous I/O operations, although the increased complexity can be hidden by implementing separate native I/O processes which cooperate with green threads.
Read more about this topic: Green Threads
Famous quotes containing the word performance:
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“So long as the source of our identity is external—vested in how others judge our performance at work, or how others judge our children’s performance, or how much money we make—we will find ourselves hopelessly flawed, forever short of the ideal.”
—Melinda M. Marshall (20th century)