100% tevredenheidsgarantie Direct beschikbaar na betaling Zowel online als in PDF Je zit nergens aan vast
logo-home
Eerder door jou gezocht
Eerder door jou gezocht
logo
CISC 372 Exam 1 Final Questions & Answers 2024/2025 €10,74   In winkelwagen
Snel navigeren naar
Voorbeeld
  2.  
  3. CISC 372
  4.  
  5. CISC 372

Tentamen (uitwerkingen)

CISC 372 Exam 1 Final Questions & Answers 2024/2025
 15 keer bekeken  0 keer verkocht
  • Vak
  • CISC 372
  • Instelling
  • CISC 372

CISC 372 Exam 1 Final Questions & Answers 2024/2025 How do we write parallel programs? - ANSWERS- move away from single-core systems to multi-core processes (core = central processing unit, CPU) - divide the work among the processes/threads -- try to balance the work so each process has ro...

[Meer zien]

Voorbeeld 4 van de 35  pagina's

Document informatie

  • 8 augustus 2024
  • 35
  • 2024/2025
  • Tentamen (uitwerkingen)
  • Vragen en antwoorden

Onderwerpen

  • cisc 372 exam 1 final questions answers 2024202

Geschreven voor

  • CISC 372
  • CISC 372

Verkoper

avatar-seller
Bensuda

Ontvangen beoordelingen

Voorbeeld van de inhoud

CISC 372 Exam 1 Final Questions &
Answers 2024/2025

How do we write parallel programs? - ANSWERS- move away from single-core systems to multi-core
processes

(core = central processing unit, CPU)

- divide the work among the processes/threads

-- try to balance the work so each process has roughly the same amount

-- minimize required communication as this is usually a bottleneck & leads to issues

- arrange for a way to synchronize the different processes during both execution & completion

- arrange for communication among processes where necessary to complete work, should be minimized



Task parallelism - ANSWERS- partition various tasks carried out solving the problem among the cores

- Ex.: Questions per TA



Data parallelism - ANSWERS- partition the data used in solving the problem among the cores

- each core carries out similar operations on its part of the data

- Ex.: Exams per TA



Coordination - ANSWERS- cores usually need to coordinate their work

- Communication

- Load balancing

- Synchronization



Communication - ANSWERS- 1+ cores send their current partial sums to another core



Load Balancing - ANSWERS- share the work evenly among the cores so that one is not more heavily
loaded

,Synchronization - ANSWERS- because each core works at its own pace, make sure cores do not get too
far ahead of the rest



C programming: Array Types Declaration - ANSWERS- double a[ ] - unspecified length, incomplete type

- double a[100] - length 100, complete type



C programming: complete type - ANSWERSrequired:

- whenever space must be allocated for the array

- an ordinary (not parameter) declaration of a local/global variable of array type

- element type of an array must be a complete type



C programming: pointers - ANSWERS- memory address of smoe location in memory

- have types which denote the type of object stored at that memory location

- pointer variable contains the memory address of some data that will be interpreted as whatever
declared type

- &, address of - returns the address of that variable

- *, dereference - returns the value stored at that address



C programming: pointers & arrays - ANSWERS- array of arrays (array of pointers)

- one big array (single malloc call)



C programming: pointer arithmetic - ANSWERSif p is a pointer to type T (a complete type) & i is an
integer, then:

- p + i is of type pointer to T

- points to the address that is i T's past p

- sizeof(T) is n bytes, then p + i is i * n bytes after p

,C programming: allocation & deallocation of arrays - ANSWERS- malloc: consumes an argument of type
integer that is the number of bytes to allocate & returns void* pointer that is the address of the first byte
of the block of allocated memory

- int *p = (int*)malloc(10*sizeof(int));, allocates space for 10 ints



- free: consumes void* pointer previously produced by malloc

- can pass in any pointer type, converted automatically

- deallocates the object off of the heap & frees up space



computer architecture basics - ANSWERS- computer CPU cores can only run one program at a time

- modern OSs simulate multiple things running at the same time by scheduling programs & swapping
them in & out of the CPU quickly

- multi-core systems can do more than one thing at a time, but still each program can only run one CPU
at a time



von Neumann architecture - ANSWERSmain memory:

- collection of locations, each which can store both instructions & data

- every location consists of an address, which is used to access the location & contents of the location



central processing unit (CPU):

- control unit: responsible for deciding which instruction in a program should be executed (the boss)

- ALU: responsible for executing the actual instructions (the worker)



Memory -> fetch/read -> CPU -> write/store -> memory - ANSWERSlead to a bottleneck architecture, as
this operation is substantially slower than anything else



caching - ANSWERS- a high-speed data storage layer which stores a subset of data; transient in nature

- extremely fast memory type that acts as a buffer between RAM & CPU; holds frequently requested
data & instructions so that they are immediately available to the CPU when needed

- primary bottleneck: read/fetch, write/store operations to main memory

, - places fast small memory near the CPU & tries to keep the data we will need in there as much as
possible



cache levels - ANSWERS- made up of multiple levels/hierarchy

- very small, very fast caches closer to the CPU (on the chip)

- larger & slower caches above them

- main memory is even larger & slower & secondary storage (i.e. disks) represent the highest level where
things don't fit in memory & can be stored until needed



principle of locality - ANSWERS- accessing one location is usually followed by access to nearby location

- spatial locality: accessing a nearby location

- temporal locality: likely access the same memory again, if it has been accessed recently ; keep accessing
"i" over & over again



cache hit - ANSWERSfind where the data location wanted has been placed in the cache



cache miss - ANSWERSdon't find the data location wanted & must go to main memory to fetch/write it,
usually adding it to the cache due to the principle of locality



mapping (cache) - ANSWERS- how cache is built so that we can find what we are looking for

- directed mapped: each memory location will always go to the same place in the cache, many-to-one
mapping; each cache line has a unique location in the cache to which it will be assigned

- full associative cache: data can be placed anywhere in the cache; a new line can be placed at any
location in the cache

- set associative cache: each data element from memory has some fixed number of possible locations to
be placed in



issues with cache - ANSWERS- when a CPU writes data to cache, the value in cache may be inconsistent
with the value in main memory

- write-through: caches handle this by updating the data in main memory at the time it's written to
cache

Voordelen van het kopen van samenvattingen bij Stuvia op een rij:

√ Verzekerd van kwaliteit door reviews

√ Verzekerd van kwaliteit door reviews

Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!

Snel en makkelijk kopen

Snel en makkelijk kopen

Je betaalt supersnel en eenmalig met iDeal, Bancontact of creditcard voor de samenvatting. Zonder lidmaatschap.

Focus op de essentie

Focus op de essentie

Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!

Veelgestelde vragen

Wat krijg ik als ik dit document koop?

Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.

Tevredenheidsgarantie: hoe werkt dat?

Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.

Van wie koop ik deze samenvatting?

Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper Bensuda. Stuvia faciliteert de betaling aan de verkoper.

Zit ik meteen vast aan een abonnement?

Nee, je koopt alleen deze samenvatting voor €10,74. Je zit daarna nergens aan vast.

Is Stuvia te vertrouwen?

4,6 sterren op Google & Trustpilot (+1000 reviews)

Afgelopen 30 dagen zijn er 75632 samenvattingen verkocht

Opgericht in 2010, al 14 jaar dé plek om samenvattingen te kopen

Start met verkopen
€10,74
  • (0)
  Kopen