Dynamic Memory Allocation

Question 1

What is Throughput?

Answer 1

• Number of completed requests per unit time
• Ex: 5,000 mallocs and 5,000 frees in 10 seconds; Throughput = 1,000 operations/second

Question 2

Goals of performance

Answer 2

Maximize throughput and peak memory utilization; These goals are often conflicting

Question 3

What is Peak Memory Utilization?

Answer 3

Pk/Hk

Pk: sum of current payloads allocated
Hk: Current Heap Size

Question 4

Types of fragmentation?

Answer 4

Internal/External Fragmentation

Question 5

What is internal fragmentation?

Answer 5

If the payload is smaller than the block size; Depends on pattern of previous requests (easy to measure)

Question 6

What is external fragmentation?

Answer 6

Enough aggregate heap memory, but no single free block large enough; Depends on pattern of future requests (hard to measure)