264 Week 12 notes

Readings (from BOH3)

Section 3.1
Section 3.2
Section 3.3
Section 3.4
Section 3.5

Chapter 6: The Cache

Temporal v Spatial locality

• temporal: if x is accessed, x is likely to be accessed again
• spatial: if x is accessed, locations near x are likely to be accessed again

Memory pyramid:

Memory mountain:

What is going on here? Height represents throughput, higher for caches.

"Prefetch line": back side, center left, perpendicular to stride axis and with throughput ~12.5 GB/s. Top edge of the "snowfield".

cache timings

Start at Seeing the Cache Size

Friday: finish matrix loop-reordering

malloc() and free()

sdir_free.c: one malloc() and one free(), both in printdir()

sdir_free2.c: the malloc() has moved to readdirentries().

sdir_free3.c: what about the malloc() in cat3()??

Why C can't have garbage collection