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Why HTM/STM in general will not allow concurrent execution in practice
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amin...@gmail.com
Sep 12, 2019, 2:34:43 PM9/12/19
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Hello,
Why HTM/STM in general will not allow concurrent execution in practice
Back in 2006-2010 Azul made custom hardware for running Big Business Java — basically a super-computer for running e.g. web portals written in Java. The hardware had many innovations, and most were geared towards Java's special needs (read barriers for low-latency GC, support range-checked array operations, virtual calls). Probably the most innovative hardware was the Hardware Transactional Memory — the entire L1 of every one of the 864 cores could do a transactional update! This was specifically designed to allow transactional update of Java locks — to allow concurrent execution of Java synchronized blocks as long as there was no actual memory update conflict.
The HTM was really strong — transactions could be as large as the entire L1 cache — yet in practice it was not good enough to run Java synchronized blocks concurrently. Cliff will tell you why it didn't work and why HTM/STM in general will not allow concurrent execution in practice.
Read more here:
https://hydraconf.com/2019/talks/2jix5mst7iduyp9linqhfj/
Thank you,
Amine Moulay Ramdane.
Why HTM/STM in general will not allow concurrent execution in practice
Back in 2006-2010 Azul made custom hardware for running Big Business Java — basically a super-computer for running e.g. web portals written in Java. The hardware had many innovations, and most were geared towards Java's special needs (read barriers for low-latency GC, support range-checked array operations, virtual calls). Probably the most innovative hardware was the Hardware Transactional Memory — the entire L1 of every one of the 864 cores could do a transactional update! This was specifically designed to allow transactional update of Java locks — to allow concurrent execution of Java synchronized blocks as long as there was no actual memory update conflict.
The HTM was really strong — transactions could be as large as the entire L1 cache — yet in practice it was not good enough to run Java synchronized blocks concurrently. Cliff will tell you why it didn't work and why HTM/STM in general will not allow concurrent execution in practice.
Read more here:
https://hydraconf.com/2019/talks/2jix5mst7iduyp9linqhfj/
Thank you,
Amine Moulay Ramdane.
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