Installation
------------

1. Configure "Class based physical memory controller" under CKRM (see
      Documentation/ckrm/installation) 

2. Reboot the system with the new kernel.

3. Verify that the memory controller is present by reading the file
   /rcfs/taskclass/config (should show a line with res=mem)

Usage
-----

For brevity, unless otherwise specified all the following commands are
executed in the default class (/rcfs/taskclass).

Initially, the systemwide default class gets 100% of the LRU pages, and the
stats file at the /rcfs/taskclass level displays the total number of
physical pages.

   # cd /rcfs/taskclass
   # grep System stats
   System: tot_pages=239778,active=60473,inactive=135285,free=44555
   # cat shares
   res=mem,guarantee=-2,limit=-2,total_guarantee=100,max_limit=100

   tot_pages - total number of pages
   active    - number of pages in the active list ( sum of all zones)
   inactive  - number of pages in the inactive list ( sum of all zones)
   free      - number of free pages (sum of all zones)

   By making total_guarantee and max_limit to be same as tot_pages, one can 
   make the numbers in shares file be same as the number of pages for a
   class.

   # echo 'res=mem,total_guarantee=239778,max_limit=239778' > shares
   # cat shares
   res=mem,guarantee=-2,limit=-2,total_guarantee=239778,max_limit=239778

Changing configuration parameters:
----------------------------------
For description of the paramters read the file mem_rc.design in this same directory.

Following is the default values for the configuration parameters:

   localhost:~ # cd /rcfs/taskclass
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=110,shrink_at=90,shrink_to=80,num_shrinks=10,shrink_interval=10

Here is how to change a specific configuration parameter. Note that more than one 
configuration parameter can be changed in a single echo command though for simplicity
we show one per echo.

ex: Changing fail_over: 
   localhost:/rcfs/taskclass # echo "res=mem,fail_over=120" > config
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=120,shrink_at=90,shrink_to=80,num_shrinks=10,shrink_interval=10

ex: Changing shrink_at: 
   localhost:/rcfs/taskclass # echo "res=mem,shrink_at=85" > config
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=120,shrink_at=85,shrink_to=80,num_shrinks=10,shrink_interval=10

ex: Changing shrink_to: 
   localhost:/rcfs/taskclass # echo "res=mem,shrink_to=75" > config
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=120,shrink_at=85,shrink_to=75,num_shrinks=10,shrink_interval=10

ex: Changing num_shrinks: 
   localhost:/rcfs/taskclass # echo "res=mem,num_shrinks=20" > config
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=120,shrink_at=85,shrink_to=75,num_shrinks=20,shrink_interval=10

ex: Changing shrink_interval: 
   localhost:/rcfs/taskclass # echo "res=mem,shrink_interval=15" > config
   localhost:/rcfs/taskclass # cat config
   res=mem,fail_over=120,shrink_at=85,shrink_to=75,num_shrinks=20,shrink_interval=15

Class creation 
--------------

   # mkdir c1

Its initial share is DONT_CARE. The parent's share values will be unchanged.

Setting a new class share
-------------------------
	
   # echo 'res=mem,guarantee=25000,limit=50000' > c1/shares

   # cat c1/shares	
   res=mem,guarantee=25000,limit=50000,total_guarantee=100,max_limit=100
	
   'guarantee' specifies the number of pages this class entitled to get
   'limit' is the maximum number of pages this class can get.

Monitoring
----------

stats file shows statistics of the page usage of a class
   # cat stats
   ----------- Memory Resource stats start -----------
   System: tot_pages=239778,active=60473,inactive=135285,free=44555
   Number of pages used(including pages lent to children): 196654
   Number of pages guaranteed: 239778
   Maximum limit of pages: 239778
   Total number of pages available(after serving guarantees to children): 214778
   Number of pages lent to children: 0
   Number of pages borrowed from the parent: 0
   ----------- Memory Resource stats end -----------