Can someone explain the differences between SCHED_OTHER, SCHED_FIFO and SCHED_RR?
有人可以解释SCHED_OTHER，SCHED_FIFO和SCHED_RR之间的区别吗？
Thanks
谢谢
1 个解决方案
#1
39
SCHED_FIFO and SCHED_RR are so called "real-time" policies. They implement the fixed-priority real-time scheduling specified by the POSIX standard. Tasks with these policies preempt every other task, which can thus easily go into starvation (if they don't release the CPU).
SCHED_FIFO和SCHED_RR是所谓的“实时”策略。它们实现POSIX标准指定的固定优先级实时调度。具有这些策略的任务会抢占所有其他任务，因此很容易陷入饥饿（如果他们不释放CPU）。
The difference between SCHED_FIFO and SCHED_RR is that among tasks with the same priority, SCHED_RR performs a round-robin with a certain timeslice; SCHED_FIFO, instead, needs the task to explicitly yield the processor.
SCHED_FIFO和SCHED_RR之间的区别在于具有相同优先级的任务中，SCHED_RR执行具有特定时间片的循环;相反，SCHED_FIFO需要任务明确地产生处理器。
SCHED_OTHER is the common round-robin time-sharing scheduling policy that schedules a task for a certain timeslice depending on the other tasks running in the system.
SCHED_OTHER是常见的循环时间共享调度策略，它根据系统中运行的其他任务来调度特定时间片的任务。
Update: since Linux 3.14, there is an additional policy called SCHED_DEADLINE. This policy implements the Constant Bandwidth Server (CBS) algorithm on top of Earliest Deadline First queues. Each task under this policy is assigned a deadline, and the earliest-deadline task is executed. The best resource describing this algorithm is Deadline scheduling in the Linux kernel.
更新：自Linux 3.14起，还有一个名为SCHED_DEADLINE的附加策略。此策略在最早期限第一个队列之上实现恒定带宽服务器（CBS）算法。为此策略下的每个任务分配一个截止日期，并执行最早期限任务。描述该算法的最佳资源是Linux内核中的截止日期调度。
Update 2: since Linux 4.13, SCHED_DEADLINE has replaced CBS with the Greedy Reclamation of Unused Bandwidth (GRUB) algorithm.
更新2：自Linux 4.13起，SCHED_DEADLINE已将CBS替换为未使用带宽的贪婪回收（GRUB）算法。
#1
39
SCHED_FIFO and SCHED_RR are so called "real-time" policies. They implement the fixed-priority real-time scheduling specified by the POSIX standard. Tasks with these policies preempt every other task, which can thus easily go into starvation (if they don't release the CPU).
SCHED_FIFO和SCHED_RR是所谓的“实时”策略。它们实现POSIX标准指定的固定优先级实时调度。具有这些策略的任务会抢占所有其他任务，因此很容易陷入饥饿（如果他们不释放CPU）。
The difference between SCHED_FIFO and SCHED_RR is that among tasks with the same priority, SCHED_RR performs a round-robin with a certain timeslice; SCHED_FIFO, instead, needs the task to explicitly yield the processor.
SCHED_FIFO和SCHED_RR之间的区别在于具有相同优先级的任务中，SCHED_RR执行具有特定时间片的循环;相反，SCHED_FIFO需要任务明确地产生处理器。
SCHED_OTHER is the common round-robin time-sharing scheduling policy that schedules a task for a certain timeslice depending on the other tasks running in the system.
SCHED_OTHER是常见的循环时间共享调度策略，它根据系统中运行的其他任务来调度特定时间片的任务。
Update: since Linux 3.14, there is an additional policy called SCHED_DEADLINE. This policy implements the Constant Bandwidth Server (CBS) algorithm on top of Earliest Deadline First queues. Each task under this policy is assigned a deadline, and the earliest-deadline task is executed. The best resource describing this algorithm is Deadline scheduling in the Linux kernel.
更新：自Linux 3.14起，还有一个名为SCHED_DEADLINE的附加策略。此策略在最早期限第一个队列之上实现恒定带宽服务器（CBS）算法。为此策略下的每个任务分配一个截止日期，并执行最早期限任务。描述该算法的最佳资源是Linux内核中的截止日期调度。
Update 2: since Linux 4.13, SCHED_DEADLINE has replaced CBS with the Greedy Reclamation of Unused Bandwidth (GRUB) algorithm.
更新2：自Linux 4.13起，SCHED_DEADLINE已将CBS替换为未使用带宽的贪婪回收（GRUB）算法。