Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
parallelism_dinamica [2020/04/08 20:07]
argemiro
parallelism_dinamica [2020/04/08 20:19] (current)
argemiro
Line 3: Line 3:
 ==== What is Parallelism?​ ==== ==== What is Parallelism?​ ====
 \\ \\
-The term Parallelism (in Computer Science) refers to a technique that allow two or more computing tasks to execute at the same time. This requires hardware with multiple processing units. A key problem of parallelism is to reduce data dependencies in order to be able to perform computations on independent computation units with minimal communication between them. To this end, it can even be an advantage to do the same computation twice on different units.+The term Parallelism (in Computer Science) refers to a technique that allow two or more computing tasks to execute at the same time. A key problem of parallelism is to reduce data dependencies in order to be able to perform computations on independent computation units with minimal communication between them. To this end, it can even be an advantage to do the same computation twice on different units.
 \\ \\
-==== How can Parallelism be achieved in modern systems?​==== 
 On modern systems, parallelism can be achieve in two different ways:  On modern systems, parallelism can be achieve in two different ways: 
 \\ \\
Line 15: Line 14:
 \\ \\
 Since modern processor architectures are composed of many cores, the later method strongly surpasses the former in terms of speed and ease of programming. In such systems, programmers must adapt their software to take advantage of Parallelism,​ taking into account concurrent access to data. To do that, data is usually broken into equal independent slices that are processed in different computing units but a fundamental problem arises when this data is not easily separable or is dependent of many computing iterations. In order to deal with this situation, software developers and architects developed many algorithms and techniques to minimize communication between computing units and data dependency. To this end, it can even be an advantage to do the same computation twice on different units to prevent synchronization. Since modern processor architectures are composed of many cores, the later method strongly surpasses the former in terms of speed and ease of programming. In such systems, programmers must adapt their software to take advantage of Parallelism,​ taking into account concurrent access to data. To do that, data is usually broken into equal independent slices that are processed in different computing units but a fundamental problem arises when this data is not easily separable or is dependent of many computing iterations. In order to deal with this situation, software developers and architects developed many algorithms and techniques to minimize communication between computing units and data dependency. To this end, it can even be an advantage to do the same computation twice on different units to prevent synchronization.
 +\\
 \\ \\
 ====Why is Parallelism important?​==== ====Why is Parallelism important?​====
-\\ 
 \\ \\
 Efficiently using these parallel capabilities is necessary to meet user demands for modelling complex dynamics with large datasets. However, users may be reticent to develop or adapt their current models to take advantage of these parallel environments because such development is often complicated,​ time-consuming,​ and error prone. Efficiently using these parallel capabilities is necessary to meet user demands for modelling complex dynamics with large datasets. However, users may be reticent to develop or adapt their current models to take advantage of these parallel environments because such development is often complicated,​ time-consuming,​ and error prone.
Line 28: Line 27:
 === How we change Dinamica EGO infrastructure and make everything as much parallel as possible? === === How we change Dinamica EGO infrastructure and make everything as much parallel as possible? ===
  
-Specificallywe re-designed ​the software ​to leverage available parallel hardware capabilities on any computerwhile maintaining flexibility ​for the user to develop custom ​models ​without worrying about such parallelization+Before version 5Parallelism in Dinamica EGO was handled by the Virtual Machine (VM) and the Functor Library (FL) directly, without global coordination. This caused uneven distribution of work between computing systems and sub-optional use of the machine resources. The Task Library was introduced in Dinamica EGO 5 to address such problemsby creating a global system ​for handling and processing work. We restructured ​the VM and FL sub-systems so that models ​are now broken into tasks according to computer capabilities and model semantics (i.e., the rules the computer must follow as prescribed by the model). These tasks are distributed to underlying computing systems ​such as processor cores and graphics processing units (GPU) and the workload is balanced by the use of the work-stealing approach. In version 5, every computing unit is able to manipulate and transform data in parallel (e.g., parts of an image can be read and written simultaneously) and also communicate,​ synchronize and exchange data with its siblings.
 \\ \\
 \\ \\
 {{ :​3c6c66e0-383c-4a1c-a9e6-b9c0d4c09fa4.jpg?​800 |}} {{ :​3c6c66e0-383c-4a1c-a9e6-b9c0d4c09fa4.jpg?​800 |}}
-\\ 
- 
-We restructured the core of the software so that models are now broken into tasks according to computer capabilities and model semantics (i.e., the rules the computer must follow as prescribed by the model). Tasks are then executed by a fixed number of “workers” using a 
-work-stealing approach. These workers can manipulate data in parallel (e.g., parts of an image can be read and written ​ simultaneously) and compute certain tasks using graphics processing units. ​ 
-\\ 
-\\ 
 \\ \\
 \\ \\
Line 46: Line 39:
  
 ===Parallelism in Dinamica EGO 4 Vs Parallelism in Dinamica EGO 5 === ===Parallelism in Dinamica EGO 4 Vs Parallelism in Dinamica EGO 5 ===
-{{ :p1.png?600 |}} +
-\\ +
-{{ :p2.png?600 |}} +
-\\ +
-{{ :p3.png?600 |}} +
-\\ +
-{{ :p4.png?600 |}} +
-\\ +
-{{ :p5.png?600 |}}+
 \\ \\
-{{ :p6.png?600 |}}+{{:parel_2.png?800 |}}
 \\ \\
 \\ \\