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