updated scheduler tunables

diff -urN linux-2.5.56/Documentation/filesystems/proc.txt linux/Documentation/filesystems/proc.txt
@@ -37,6 +37,7 @@
   2.8	/proc/sys/net/ipv4 - IPV4 settings
   2.9	Appletalk
   2.10	IPX
+  2.11  /proc/sys/sched - scheduler tunables
 
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 Preface

@@ -1663,6 +1664,92 @@
 gives the  destination  network, the router node (or Directly) and the network
 address of the router (or Connected) for internal networks.
 
+2.11 /proc/sys/sched - scheduler tunables
+-----------------------------------------
+
+Useful knobs for tuning the scheduler live in /proc/sys/sched.
+
+child_penalty
+-------------
+
+Percentage of the parent's sleep_avg that children inherit.  sleep_avg is
+a running average of the time a process spends sleeping.  Tasks with high
+sleep_avg values are considered interactive and given a higher dynamic
+priority and a larger timeslice.  You typically want this some value just
+under 100.
+
+exit_weight
+-----------
+
+When a CPU hog task exits, its parent's sleep_avg is reduced by a factor of
+exit_weight against the exiting task's sleep_avg.
+
+interactive_delta
+-----------------
+
+If a task is "interactive" it is reinserted into the active array after it
+has expired its timeslice, instead of being inserted into the expired array.
+How "interactive" a task must be in order to be deemed interactive is a
+function of its nice value.  This interactive limit is scaled linearly by nice
+value and is offset by the interactive_delta.
+
+max_sleep_avg
+-------------
+
+max_sleep_avg is the largest value (in ms) stored for a task's running sleep
+average.  The larger this value, the longer a task needs to sleep to be
+considered interactive (maximum interactive bonus is a function of
+max_sleep_avg).
+
+max_timeslice
+-------------
+
+Maximum timeslice, in milliseconds.  This is the value given to tasks of the
+highest dynamic priority.
+
+min_timeslice
+-------------
+
+Minimum timeslice, in milliseconds.  This is the value given to tasks of the
+lowest dynamic priority.  Every task gets at least this slice of the processor
+per array switch.
+
+parent_penalty
+--------------
+
+Percentage of the parent's sleep_avg that it retains across a fork().
+sleep_avg is a running average of the time a process spends sleeping.  Tasks
+with high sleep_avg values are considered interactive and given a higher
+dynamic priority and a larger timeslice.  Normally, this value is 100 and thus
+task's retain their sleep_avg on fork.  If you want to punish interactive
+tasks for forking, set this below 100.
+
+prio_bonus_ratio
+----------------
+
+Middle percentage of the priority range that tasks can receive as a dynamic
+priority.  The default value of 25% ensures that nice values at the
+extremes are still enforced.  For example, nice +19 interactive tasks will
+never be able to preempt a nice 0 CPU hog.  Setting this higher will increase
+the size of the priority range the tasks can receive as a bonus.  Setting
+this lower will decrease this range, making the interactivity bonus less
+apparent and user nice values more applicable.
+
+starvation_limit
+----------------
+
+Sufficiently interactive tasks are reinserted into the active array when they
+run out of timeslice.  Normally, tasks are inserted into the expired array.
+Reinserting interactive tasks into the active array allows them to remain
+runnable, which is important to interactive performance.  This could starve
+expired tasks, however, since the interactive task could prevent the array
+switch.  To prevent starving the tasks on the expired array for too long. the
+starvation_limit is the longest (in ms) we will let the expired array starve
+at the expense of reinserting interactive tasks back into active.  Higher
+values here give more preferance to running interactive tasks, at the expense
+of expired tasks.  Lower values provide more fair scheduling behavior, at the
+expense of interactivity.  The units are in milliseconds.
+
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 Summary
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