Implementation of a Linux RR scheduler and an Android Linux group based scheduler.

Copyright (C) 2014 V. Atlidakis, G. Koloventzos, A. Papancea

COMS-W4118 Columbia University

MODIFIED/ADDED FILES:

• flo-kernel/arch/arm/configs/flo_defconfig defined CONFIG_GRR and CONFIG_GRR_GROUPS flags

• flo-kernel/arch/arm/configs/goldfish_armv7_defconfig defined CONFIG_GRR and CONFIG_GRR_GROUPS flags

• flo-kernel/arch/arm/include/asm/unistd.h defined sched_set_CPUgroup syscall at position 378

• flo-kernel/arch/arm/kernel/calls.S added syscall to syscall table at position 378

• flo-kernel/include/linux/init_task.h modified init task to be scheduled using the GRR policy

• flo-kernel/include/linux/sched.h modified sched.h for various headers and structs used within the assignment; primarily, we defined SCHED_GRR policy, sched_grr_entity

• flo-kernel/include/linux/syscalls.h defined the syscall sched_set_CPUgroup

• flo-kernel/init/Kconfig more setup for the CONFIG_GRR and CONFIG_GRR_GROUPS flags

• flo-kernel/kernel/kthread.c added sched_setscheduler_nocheck() function for the GRR policy

• flo-kernel/kernel/sched/Makefile added grr.c binary to the kernel compilation

• flo-kernel/kernel/sched/core.c implementation of the sched_set_CPUgroup syscall, as well as matching relevant code to the other scheduling policies; added timer for the GRR load balancer

• flo-kernel/kernel/sched/debug.c added print_grr_rq function for GRR debugging

• flo-kernel/kernel/sched/grr.c GRR class implementation

• flo-kernel/kernel/sched/rt.c added grr_sched_class as the next scheduling class after the realtime scheduling class

• flo-kernel/kernel/sched/sched.h modified sched.h for various headers and structs used within the assignment; primarily, we defined SCHED_GRR policy, sched_grr_entity

• test/Makefile Makefile for the test program

• test/set_sched_policy.c test program that auto-schedules itself using the GRR class

• test/test.c test program that assigns cores to groups

BRANCHES AND EXERCISE PARTS

uniprocessor_rr -> Here you can find the round robin algorithm for a uniprocessor. We have left 2 print statements in pick_next_task and enqueue in order to see that the RR algorithm takes place.

smp_devel -> Here you can find the part 2 of our assignment.

RESOURCES USED:

1. Linux Cross Reference http://lxr.free-electrons.com

2. Linux Kernel Development (3rd Edition)

3. Operating Systems: Principles and Practice (2nd Edition)