Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.programming.threads > #1964

Optimistic sycnhronisation

Cross-posted to 2 groups.

Show all headers | View raw

Hello,

I have come to an interresting subject...

I was thinking more about my ParallelVarFiler and about database 
engines, first i have told you that since database engines are disk
bound and/or memory bound that means that they are not scalable
in multicores systems, but more than that that i was thinking more
and asking my self why to use optimistic synchronization mechanism like 
in transactional memory ? i think that an optimistic synchronization 
mechanism like in transactional memory can give better throughput and 
better speed, prof of that ? take a look at my ParallelVarFiler for 
exemple,
since it can be disk bound when you are saving automaticly the
data to a disk file that means that there is no need to use
an RWLock since the hardisk is not trully parallel.. so a Lock will have
the same performance as an RWLock in a disk bound scenario, it's why i 
have used a FIFO fair Lock inside my ParallelVarFiler, but if the 
hardisk or memory can be truly parallel an RWLock will be better ,
it's the same with an optimistic sychronization like in transactional 
memory, first you have to know that a Lock will serialize the read and 
write transactions, an RWLock will parallelize the read transaction, but 
  with optimistic synchronization mechanism like in transactional memory 
you can have in theory many writes transactions in parallel
and many read transactions in parallel , but since the hardisk is not 
truly parallel, this
optimistic synchronization like in transactional memory will not bring
better performance than a RWLok , so i think that transactional memory and
optimistic synchronization can not give better performance if the 
hardisk and memory are not trully parallel, but since the memory system
and hardisk system is not truly parallel today, so this
optmistic schychronisation that is using transactional memory or other 
systemes, will not bring you better performance than a RWLock.


Thank you,
Amine Moulay Ramdane.

Back to comp.programming.threads | Previous | Next | Find similar

Thread

Optimistic sycnhronisation aminer <aminer@toto.net> - 2013-10-27 22:59 -0700

csiph-web