Resource conflict resolution

This chapter describes algorithms for resource conflict resolution. Resource conflicts occur when multiple operations activate the same hardware resource simultaneously. When all operations in the hardware model have fixed execution delays, conflict resolution becomes part of the scheduling and resource binding tasks. In particular, operations scheduled to different control stq)s or belonging to mutually exclusive conditional branches can share their hardware resources. Consider for example the force-directed scheduling technique [PK89b]. Operations with similar resources are first scheduled to reduce their concurrency, then they are bound to hardware resources subject to this schedule. The binding step ensures that no resource conflicts will arise. This approach is, however, restricted to bounded delay operations. 

---

Resource conflict resolution. A resource binding implies a cotain configuration of hardware sharing. In general, resource conflicts can arise when a resource is accessed simultaneously by multiple op tions. These conflicts can be resolved by serializing operations bound to the same resource that can otherwise execute in parallel. Timing constraints must still be satisfied after conflict resolution. 

For ease of presentation, relative scheduling is first described in Chapter 6, where resource conflicts are assumed to be resolved. Resource conflict resolution by appropriately serializing the operations subject to the timing constraints is presented in Chapter 7. Control generation from relative scheduling is described in Chapter 8. A novel approach to control optimization called resynchronization is described in Chapter 9. 

It will be clear that conflicts of resource availability and utilization will occur. Conflict resolution and overall guidance of the various Therapeutic Team programs is handled by a committee of the most senior executives in the research organisation, if conflicts cannot be resolved at a lower level. 

Resource Management. It is necessary to document in procedures of the integrated management system the processes of staff selection, reception and training, health surveillance of the workers, PPE s management, worker representation, performance evaluation, evaluation of the working environment and conflict resolution. 

Other specific tools can help analyze the workplace. Occupational Safety and Health Administration (OSHA) has voluntary and advisory guidelines relating to workplace violence, stress reduction, conflict resolution, risk assessment, and health issues related to this hazard. The National Institute for Occupational Safety and Health (NIOSH) has similar resources available. Many other private organizations will provide information and leads to professionals who practice the services needed. Of course, all of these organizations should be used throughout the process of developing and implementing the plan. 

Constrained conflict resolution a method to resolve resource conflicts under timing constraints,... 

On the other hand, if the conflict-free allocation exceeds resource constraints, then additional hardware sharing is required. This results in resource conflicts that must be resolved. Conflict resolution is the subject of Chapter 7. 

Serialization cost C,trial- Resource conflicts may arise due to a binding. Determining whether a conflict resolution exists under timing constraints is computationally expensive. Therefore, the conflict degree of Section 5.2 is used to estimate the number of threads of parallelism that need to be serialized in order to resolve the resource conflicts. C,trial is a heuristic... 

Organization of chapter. This chapter presents the formulation and algorithms for relative scheduling. Our approach can be described in a nutshell as follows. In relative scheduling, we support both operations with fixed delay and operations with data-dependent delay data-dependent delay operations represent points of synchronization. We uniformly model both types of operations as vertices in the constraint graph model. We assume in this cluq)ter that resource binding and conflict resolution have been performed prior to scheduling. 

The objective in conflict resolution is to resolve the conflicts among elements of a candidate operation set 0(t,)(G), which is derived from a resource binding / and a constraint graph model G V, E). An ordering of the instance operation set is defined as follows. 

We make the following assumptions. First, the cardinality of the operation cluster must be greater than one ( C > 1), since othowise the ordering is trivial. Second, each vertex Cj C must either be a data-dependent delay operation (i.e. anchor) or have non-zero fixed execution delay, i.e. (c ) > 0. Note that registers have already been introduced prior to conflict resolution to latch the outputs of the shared resource. For example, the execution delay for shared calls to a combinational adder is 1 cycle because of the latching delay. 

Algorithms for conflict resolution is presented in this section. The input is a resource binding consisting of a number of instance operation sets. The instance op tion sets in / are selected in turn. For a given instance operation set O, its operation clusters are first identified using standard graph techniques... 

This section presented algorithms to resolves the conflicts that arise when multiple operations share the same hardware resource. In traditional synthesis approaches that consider only operations with bounded execution delays, conflict resolution is defined as part of the scheduling and resource binding tasks. These approaches are inappropriate for the sequoicing graph model because of its support for data-dependent delay opmtions. 

Each design point represents a particular resource binding configuration for which a valid conflict resolution exists. These points are written to the file system so that at a later session with Hebe, they can be retrieved and presented to the designer for synthesis. 

KM91a] D. C. Ku and G. De Micheli. Constrained conflict resolution and resource sharing in Hebe. INTEGRATION, the VLSI Journal, Vol. 12 pp. 131-165, December 1991. 

---