介绍下 CPU 高速缓存和 Java 相关问题。

1. Java CPU
2016.07.20

2. •
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•
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4. •
• Direct Mapping
• N-way Mapping
•
• LRU
• RND
•
• write through
• write back
• CPU cache line
•
•

5. Mac Cache
• sudo sysctl -a | grep cache

7. Cache Coherence
• MESI https://en.wikipedia.org/wiki/MESI_protocol
• write back
•
• Cache line: dirty valid
• Modified
Cache
• Exclusive Cache
• Shared Cache
• Invalid

8. MESI
RFO: Request For Owner

9. MESI
• http://blog.csdn.net/muxiqingyang/article/details/6615199

10. Java
•
• L1CacheMiss.java
• duration = 701358693
• duration = 10996917277

11. Java
• False Sharing

12. False sharing
• Java 8:
• @sun.misc.Contended
• -XX:-RestrictContended
• FalseSharing.java
• duration = 27174444875
• duration = 3928016195
• duration = 3926949331

13. • https://en.wikipedia.org/wiki/CPU_cache
• http://blog.csdn.net/robertsong2004/article/details/38340247
• https://en.wikipedia.org/wiki/MESI_protocol
• http://blog.csdn.net/realxie/article/details/7317630
• http://mechanical-sympathy.blogspot.jp/2011/07/false-sharing.html
• http://coderplay.iteye.com/blog/1485760
• http://coderplay.iteye.com/blog/1486649
• http://psy-lob-saw.blogspot.jp/2013/05/know-thy-java-object-memory-
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