1. 2 – Operating Systems
Marian Marinov Borislav Varadinov
CEO of 1H Ltd. System Administrator
mm@1h.com bobi [ at ] itp.bg

4. What is Operating System?
➢ To manages hardware resources.
➢ To provides common services for
the application developers.
➢To acts as an intermediary
between the user(s) and the
computer system. From a user’s
point of view, the operating system
is there to execute programs.

5. ➢Non-interrupted execution
➢Interrupted execution

6. Arduino example

7. Arduino example

8. Kernel architecture
l space
Kerne
e
User spac

9. Monolithic kernels

10. Micro kernels

11. Hybrid kernels

12. Kernel architectures

13. Kernel software
➢ CPU Handling
➢ Memory Manager
➢ Interrupt handler
➢ Device drivers
➢ File systems
➢ Network
➢ CPU Scheduler
➢ I/O Scheduler
➢ Network Scheduler
➢ Security mechanisms

14. Multi-platform
➢ 27 CPU Architectures
➢ x86 / x86_64
➢ RISC / PA-RISC
➢ SPARC
➢ ARM
➢ 24 x86 CPU types
➢ 486/586/K5...
➢ Athlon/Opteron
➢ Cyrix
➢ AMD Elan
➢ Winchip
➢ Intel Pentium*, Atom, Core*

15. Memory Manager (MM)
➢ Does the physical memory allocation
➢ Implements Physical Address Extension
(PAE)
➢ Linux specific allocation
➢ SLAB – per cpu and per node queues
➢ SLUB – faster and default
➢ SLOB – fragmentation
➢ Memory compaction
➢ Huge pages

16. Interrupt Manager
➢This code is a simple
dispatcher of events

17. Device drivers....

18. File Systems
➢ The Virtual File System(VFS) layer is the
'One ring to rule them all' system in terms of
file systems.
➢ It is responsible for the main file system
cache

19. ➢ Devices
Network Et
W he
W i F i rn
G iM et
➢ Drivers A PR ax
m S
at /H
➢ Protocols eu S
r R DP
ad A
io
ARP
IP
MP
IC P
UD
SC TCP
DC TP
RD CP
Tu AN es
B. S
VL idg
A.
nn s
s
T.M
el
Br
.A
.N
.

20. Types of Operating Systems
➢ Single/Multi-platform
➢ Single/Multi-processing
➢ Single/Multi-tasking
➢ Cooperative
➢ Preemptive
➢ Single/Multi-threading
➢ Single/Multi-user
➢ Real-time

21. Thread scheduling
➢ Windows
➢ Linux
- Completely Fair Scheduler (CSF)
- Niceness
CPU Core 0 CPU Core 1
Level 00
Level 0 Level -19
Level 00
Level 0
PIDLevelTICKS
Level 0
PID TICKS PIDLevelTICKS
PID TICKS
PID TICKS PID TICKS
21426 185TICKS
PID 185
21426 31512 132TICKS
PID
21426 185 21426 185
64723 200185
21426 21426 185
64723 200 34231 94 185
21426
64723 200
64723 200 64723 200
64723 200 64723 200

22. I/O scheduling
➢Linux I/O schedulers
➢ Completely Fair Queuing - per-process
queues and then allocates time slices for
each of the queues to access the disk
➢ Anticipatory - "anticipating" synchronous
read, good for video streaming
➢ Deadline - imposing a deadline on all I/O
operations to prevent starvation of requests
➢ Noop - simple FIFO queue and implements
request merging

23. Network scheduling
➢ Windows
➢ Linux
➢ Traffic queuing with
different 23 different QoS
mechanisms
➢ INGRESS and
EGRESS queuing

24. Hardware
http://academy.telerik.com/student-courses/software-technologies/os-windows-linux/

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