sched, documentation: remove old O(1) scheduler document

Since we don't have O(1) scheduler implementation anymore,
remove the legacy doc.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 126 deletions

diff --git a/Documentation/scheduler/sched-coding.txt b/Documentation/scheduler/sched-coding.txt
deleted file mode 100644
index cbd8db752acf..000000000000
--- a/Documentation/scheduler/sched-coding.txt
+++ /dev/null
@@ -1,126 +0,0 @@
-     Reference for various scheduler-related methods in the O(1) scheduler
-                Robert Love <rml@tech9.net>, MontaVista Software
-
-
-Note most of these methods are local to kernel/sched.c - this is by design.
-The scheduler is meant to be self-contained and abstracted away.  This document
-is primarily for understanding the scheduler, not interfacing to it.  Some of
-the discussed interfaces, however, are general process/scheduling methods.
-They are typically defined in include/linux/sched.h.
-
-
-Main Scheduling Methods
------------------------
-
-void load_balance(runqueue_t *this_rq, int idle)
-        Attempts to pull tasks from one cpu to another to balance cpu usage,
-        if needed.  This method is called explicitly if the runqueues are
-        imbalanced or periodically by the timer tick.  Prior to calling,
-        the current runqueue must be locked and interrupts disabled.
-
-void schedule()
-        The main scheduling function.  Upon return, the highest priority
-        process will be active.
-
-
-Locking
--------
-
-Each runqueue has its own lock, rq->lock.  When multiple runqueues need
-to be locked, lock acquires must be ordered by ascending &runqueue value.
-
-A specific runqueue is locked via
-
-        task_rq_lock(task_t pid, unsigned long *flags)
-
-which disables preemption, disables interrupts, and locks the runqueue pid is
-running on.  Likewise,
-
-        task_rq_unlock(task_t pid, unsigned long *flags)
-
-unlocks the runqueue pid is running on, restores interrupts to their previous
-state, and reenables preemption.
-
-The routines
-
-        double_rq_lock(runqueue_t *rq1, runqueue_t *rq2)
-
-and
-
-        double_rq_unlock(runqueue_t *rq1, runqueue_t *rq2)
-
-safely lock and unlock, respectively, the two specified runqueues.  They do
-not, however, disable and restore interrupts.  Users are required to do so
-manually before and after calls.
-
-
-Values
-------
-
-MAX_PRIO
-        The maximum priority of the system, stored in the task as task->prio.
-        Lower priorities are higher.  Normal (non-RT) priorities range from
-        MAX_RT_PRIO to (MAX_PRIO - 1).
-MAX_RT_PRIO
-        The maximum real-time priority of the system.  Valid RT priorities
-        range from 0 to (MAX_RT_PRIO - 1).
-MAX_USER_RT_PRIO
-        The maximum real-time priority that is exported to user-space.  Should
-        always be equal to or less than MAX_RT_PRIO.  Setting it less allows
-        kernel threads to have higher priorities than any user-space task.
-MIN_TIMESLICE
-MAX_TIMESLICE
-        Respectively, the minimum and maximum timeslices (quanta) of a process.
-
-Data
-----
-
-struct runqueue
-        The main per-CPU runqueue data structure.
-struct task_struct
-        The main per-process data structure.
-
-
-General Methods
----------------
-
-cpu_rq(cpu)
-        Returns the runqueue of the specified cpu.
-this_rq()
-        Returns the runqueue of the current cpu.
-task_rq(pid)
-        Returns the runqueue which holds the specified pid.
-cpu_curr(cpu)
-        Returns the task currently running on the given cpu.
-rt_task(pid)
-        Returns true if pid is real-time, false if not.
-
-
-Process Control Methods
------------------------
-
-void set_user_nice(task_t *p, long nice)
-        Sets the "nice" value of task p to the given value.
-int setscheduler(pid_t pid, int policy, struct sched_param *param)
-        Sets the scheduling policy and parameters for the given pid.
-int set_cpus_allowed(task_t *p, unsigned long new_mask)
-        Sets a given task's CPU affinity and migrates it to a proper cpu.
-        Callers must have a valid reference to the task and assure the
-        task not exit prematurely.  No locks can be held during the call.
-set_task_state(tsk, state_value)
-        Sets the given task's state to the given value.
-set_current_state(state_value)
-        Sets the current task's state to the given value.
-void set_tsk_need_resched(struct task_struct *tsk)
-        Sets need_resched in the given task.
-void clear_tsk_need_resched(struct task_struct *tsk)
-        Clears need_resched in the given task.
-void set_need_resched()
-        Sets need_resched in the current task.
-void clear_need_resched()
-        Clears need_resched in the current task.
-int need_resched()
-        Returns true if need_resched is set in the current task, false
-        otherwise.
-yield()
-        Place the current process at the end of the runqueue and call schedule.