- Here is another problem with ARM processors.. - 1 Update
- My Scalable VarFiler was updated to version 1.92 - 2 Updates
| aminer68@gmail.com: Nov 18 02:26PM -0800 Hello.. Here is another problem with ARM processors.. About SC and TSO and RMO hardware memory models.. I have just read the following webpage about the performance difference between: SC and TSO and RMO hardware memory models I think TSO is better, it is just around 3% ~ 6% less performance than RMO and it is a simpler programming model than RMO. So i think ARM must support TSO to be compatible with x86 that is TSO. Read more here to notice it: https://infoscience.epfl.ch/record/201695/files/CS471_proj_slides_Tao_Marc_2011_1222_1.pdf About memory models and sequential consistency: As you have noticed i am working with x86 architecture.. Even though x86 gives up on sequential consistency, it's among the most well-behaved architectures in terms of the crazy behaviors it allows. Most other architectures implement even weaker memory models. ARM memory model is notoriously underspecified, but is essentially a form of weak ordering, which provides very few guarantees. Weak ordering allows almost any operation to be reordered, which enables a variety of hardware optimizations but is also a nightmare to program at the lowest levels. Read more here: https://homes.cs.washington.edu/~bornholt/post/memory-models.html Memory Models: x86 is TSO, TSO is Good Essentially, the conclusion is that x86 in practice implements the old SPARC TSO memory model. The big take-away from the talk for me is that it confirms the observation made may times before that SPARC TSO seems to be the optimal memory model. It is sufficiently understandable that programmers can write correct code without having barriers everywhere. It is sufficiently weak that you can build fast hardware implementation that can scale to big machines. Read more here: https://jakob.engbloms.se/archives/1435 Thank you, Amine Moulay Ramdane. |
| aminer68@gmail.com: Nov 18 10:55AM -0800 Hello, My Scalable VarFiler was updated to version 1.92 You can download it from: https://sites.google.com/site/scalable68/scalable-parallel-varfiler And the Scalable Varfiler benchmarks are here: https://sites.google.com/site/scalable68/parallel-varfiler-benchmarks Thank you, Amine Moulay Ramdane. |
| aminer68@gmail.com: Nov 18 11:18AM -0800 > https://sites.google.com/site/scalable68/parallel-varfiler-benchmarks > Thank you, > Amine Moulay Ramdane. Now ParallelVarFiler is Fault tolerant to power failures etc. i have done a simulation of power failures and data file damages and ParallelVarFiler is recovering from power failures and damages of the data file ... If AnalyzeVarfiler() returns ctCorrupt if there is a power failure or something like that that gives a corruption, you have to fix the format of the archive with FixVarfiler() that will fix the format of the archive and recover from a power failure corruption etc. Thank you, Amine Moulay Ramdane. |
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