59 lines
No EOL
1.5 KiB
Markdown
59 lines
No EOL
1.5 KiB
Markdown
## Ex. 1
|
|
### a)
|
|
Spacial locality -(constant) proximity of memory spaces relative to a reference memory space
|
|
|
|
Logically following the multiplication process of matrices, C and A have spacial locality (while B does not, due to advancing in columns and not rows). Matrix C also has temporal locality.
|
|
### b)
|
|
cache size = 25600 KB
|
|
cache line/alignment= 64 B
|
|
double -> 8
|
|
|
|
(64/8) = 8 elements
|
|
|
|
**Estimation of misses:**
|
|
- matrix C: n² / 8
|
|
- matrix B: n³
|
|
- matrix A: n³ / 8
|
|
|
|
>[!info] The difference in being divided by 8 or not comes from the spacial locality of the matrix.
|
|
|
|
>[!info]- Commands ran
|
|
>nano /proc/cpuinfo
|
|
>srun --partition=cpar perf cat /proc/cpuinfo
|
|
### c)
|
|
C -> n² / 8
|
|
B -> n³ / 8 (since it has been transpost)
|
|
C -> n³/8
|
|
|
|
### d)
|
|
|
|
| N | Version | Time | CPI | \#I| L1_DMiss (estimated) | L1_DMiss | Miss/\#I |
|
|
| --------- | --- | --- | -------- | ----------- | ---------- | -------------- | ---------- |
|
|
| 512 | base() | | 1 | 0 | 1 | 1 | 0 |
|
|
| 512 | transp() | 0 | 1 | 0 | 0 | 1 | 1 |
|
|
|
|
512x512x8 = 2 MB
|
|
512x8 = 4KB
|
|
|
|
**Base: (n=512):**
|
|
- C -> n² / 8 = 262144
|
|
- A -> n³ / 8 = 16777216
|
|
- B -> n³ ( 8) = 16777216
|
|
- Total =
|
|
|
|
**Transp: Impacto (n=512):**
|
|
- C -> n² / 8 = 262144
|
|
- A -> n² / 8 = 262144
|
|
- B -> n³ ( 8) = 16777216
|
|
- Total = 17072128
|
|
|
|
>[!note]- Commands run
|
|
>srun --partition=cpar perf stat -e L1-dcache-load-misses -M cpi ./b.out
|
|
### e)
|
|
|
|
### f)
|
|
|
|
|
|
|
|
|
|
## Ex. 2 |