Skip to main content

Next fit Algorithm for RM Scheduling

  1. This algorithm uses the same assumptions used in the Rate Monotonic Scheduling
  2. This algorithm is based on the RM Scheduling algorithm for each processors
  3. The multi processor is assumed to consists of identical processors.
  4. The tasks are assumed to require no resources other than the CPU Time
  5.  

    The tasks are allocated to processors according to the classes in which they belong. Each classes contains a set of processors that is only allocated the tasks of that class.

     

    Tasks are allocated one by one to the appropriate processor classes until all the tasks have been scheduled.

    If any class fails to produce a feasible RM Schedule, then a new processor will be added to the same class and the corresponding task (which does not meets its deadline) is allocated to the new processor class.

     

    Example

    Let us say M=4 classes. The following table lists the classes

    Class

    Bound

    C1

    (0.41,1]

    C2

    (0.26,0.41]

    C3

    (0.19,0.26]

    C4

    (0, 0.19]

     

    The tasks sets are given below

     

    T1

    T2

    T3

    T4

    T5

    T6

    T7

    T8

    T9

    T10

    T11

    ei

    5

    7

    3

    1

    10

    16

    1

    3

    9

    17

    21

    Pi

    10

    21

    22

    24

    30

    40

    50

    55

    70

    90

    95

    u(i)=ei/Pi

    0.50

    0.33

    0.14

    0.04

    0.33

    0.40

    0.02

    0.05

    0.13

    0.19

    0.22

    Class

    C1

    C2

    C4

    C4

    C2

    C2

    C4

    C4

    C4

    C4

    C3

     

    Steps

  6. Since C1 class contains only one task T1, it will be RM Schedulable, so p1 is a processor under C1
  7. C2 contains three tasks, T2, T5 and T6, upon RM Scheduling T6 fails to meets its deadline, so a new processor is added to class C2. So class C2 contains two processors p2 and p5
  8. C3 is also having only one Task T11 and it will also be schedulable under RM, so p3 is a processor under C3.
  9. C4 contains 6 tasks namely, T3,T4, T7,T8,T9 and T10. All the tasks meets their deadlines under RM Scheduling, so p4 is a processor under C4
  10.  

    Processor

    Tasks

    p1

    T1

    p2

    T2, T5

    p3

    T11

    p4

    T3,T4,T7,T8,T9,T10

    p5

    T6

     

     

Comments

Popular posts from this blog

Installing TexLive 2019 in Ubuntu 18.04

Installation of TexLive 2019 in Linux (Ubuntu 18.04 LTS)
TeX (Tech)

Installation of TexLive 2019

Please watch the video for full installation



I used .iso file to download, the Total size is 3.3GB for Linux,

and i used the torrent file to download, it took me just 20 min to download the entire .iso file

Extract the .iso file to a folder and open a terminal

$] sudo ./install-tl
(it goes into a terminal mode, which is faster compared to the GUI Mode)

$] sudo ./install-tl -gui
after the installation, set the PATH, MANPATH and INFOPATH as suggested by LATEX

export PATH=$PATH:/usr/local/texlive/2019/bin/x86_64-linux
export MANPATH=/usr/local/texlive/2019/texmf-dist/doc/man
export INFOPATH=/usr/local/texlive/2019/texmf-dist/doc/info

put these lines in to the /home/pradeepkumar/.bashrc

$] gedit /home/pradeepkumar/.bashrc
We have installed TexLive 2019 and texstudio.

To install texstudio

$] sudo apt install texstudio
The look and feel of TexStudio looks like this image.


texlive, it install everyt…

Implementing a new system call in Kernel version 2.6.32

A system call is used by application or user programs to request service from the operating systems. Since the user programs does not have direct access to the kernel whereas the OS has the direct access. OS can access the hardware through system calls only.The following files has to be modified for implementing a system call/usr/src/linux-2.6.32.5/arch/x86/kernel/syscall_table_32.S/usr/src/linux-2.6.32.5/arch/x86/include/asm/unistd_32.h/usr/src/linux-2.6.32.5/include/linux/syscalls.h/usr/src/linux-2.6.32.5/MakefileNew set of files to be createdCreate a new directory newcall/ inside the path “/usr/src/linux-2.6.32.5/” Create new files Makefile, newcall.c and put them in the /usr/src/linux-2.6.32.5/newcall/ folder Create new user files (in any folder of Linux) to test the system call
testnewcall.c, testnewcall.h (created in /home/pradeepkumar) syscall_table_32.S Find the file /usr/src/linux-2.6.32.5/arch/x86/kernel/syscall_table_32.S and add the following line at the end
"…

Electrical Machine Design (equations)

FactorsDC Machine Transformers Induction Machines Synchronous MachinesOutput EquationPa=CoD2Ln, where Pa=P/h for generators, Pa=P for motorsFor Single Phase
Q=2.22 f Bm Ai Kw Aw d10-3
For Three Phase
Q=3.33 f Bm Ai Kw Aw d 10-3Q=CoD2 L ns
KVA Input Q=
HP * 0.746 / Cos f * hQ=CoD2 L ns
KVA Input Q=
HP * 0.746 / Cos f * h
For Turbo alternators
Q=1.11Bavac KwsVa2 L 10-3/nsOutput CoefficientCo=Bav ac* 10-3where Bav-magnetic loading and ac - electric loadingDNACo=11 Kws Bav ac 10-3Co=11 Kws Bav ac 10-3 Choice of Magnetic LoadingFlux Density in Teeth Frequency of Flux Reversals Size of machineDNAMagnetizing current, Flux Density, Iron lossIron loss, Stability, Voltage Rating, Parallel Operation, Transient ShortCircuit current Choice of Electric LoadingTemperature rise,
speed of machine, Voltage, Armature reaction, CommutationDNAOverload Capacity, Copper losses, Temperature rise, Leakage ReactanceCopper loss, Synchronous reactance, Temperature rise, Stray Load losses,
Voltage rating Flux …