Change in Linux kernel scheduler function

[thendal]

I am asked to build a \pro_ler" for the Linux kernel scheduler. & to add code to the existing Linux kernel's schedule() function so that upon every 1000th call, a sequence of information is

printed to the system log _le (/var/log/messages). This information should include:

_ the PID of the process currently running on the CPU being scheduled for,

_ the total number of tasks in the active runqueue,

_ the total number of tasks in the expired runqueue,

_ the total number of tasks waiting for I/O,

_ for each possible priority:

{ if there are no processes with this priority, do nothing

{ if there are processes with this priority, then print out:

_ the priority value,

_ for each active process of this priority:

_ the process ID,

_ the executable name,

_ the time slice left,

_ the static priority,

_ the dynamic priority,

_ the interactivity count.

_ the same for each expired process of this priority.



Example Output

After booting your kernel, sections similar to this should show up in /var/log/messages:

Sep 13 15:14:42 bluehen kernel: ~~~~~~~~~ BEGIN SCHEDULER PROFILE ~~~~~~~~~

Sep 13 15:14:42 bluehen kernel: The pid running right now is 4633

Sep 13 15:14:42 bluehen kernel: The number of active tasks is 3

Sep 13 15:14:42 bluehen kernel: The number of expired tasks is 6

Sep 13 15:14:42 bluehen kernel: The number of tasks waiting on I/O is 0

Sep 13 15:14:42 bluehen kernel: =====PRIORITY: 115====

Sep 13 15:14:42 bluehen kernel: 4633(netscape-bin), TSL=106, PRS=120, PRD=115, I

C=101

Sep 13 15:14:42 bluehen kernel: ------

Sep 13 15:14:42 bluehen kernel: =====PRIORITY: 125====

Sep 13 15:14:42 bluehen kernel: ------

Sep 13 15:14:42 bluehen kernel: 4573(a.out), TSL=102, PRS=120, PRD=125, IC=-101,

Sep 13 15:14:42 bluehen kernel: 4572(a.out), TSL=102, PRS=120, PRD=125, IC=-101

Sep 13 15:14:42 bluehen kernel: =====PRIORITY: 135====

Sep 13 15:14:42 bluehen kernel: ------

Sep 13 15:14:42 bluehen kernel: 4560(a.out), TSL=53, PRS=130, PRD=135, IC=-101

Sep 13 15:14:42 bluehen kernel: =====PRIORITY: 139====

Sep 13 15:14:42 bluehen kernel: 4564(a.out), TSL=9, PRS=139, PRD=139, IC=-101,

Sep 13 15:14:42 bluehen kernel: 4563(a.out), TSL=10, PRS=139, PRD=139, IC=-101

Sep 13 15:14:42 bluehen kernel: ------

Sep 13 15:14:42 bluehen kernel: 4569(a.out), TSL=29, PRS=135, PRD=139, IC=-101,

Sep 13 15:14:42 bluehen kernel: 4567(a.out), TSL=29, PRS=135, PRD=139, IC=-101,

Sep 13 15:14:42 bluehen kernel: 4566(a.out), TSL=10, PRS=139, PRD=139, IC=-101

Appreciate any input.