False Sharing Misses: Artifactual Comm.
Different processors update different words in same block
Hardware treats it as sharing
cache block is unit of coherence
Ping-pongs between caches
P
6
P
7
P
4
P
8
P
0
P
1
P
2
P
3
P
5
Cache block
straddles partition
boundary
Contiguity in memory layout
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