#3744 new enhancement

A new Constant Bandwidth Server (CBS) version with reduced limitations.

Reported by: jollp Owned by:
Priority: normal Milestone:
Component: score Version: 5
Severity: normal Keywords:
Cc: jollp@… Blocked By:
Blocking:

Description

RTEMS provides a version of the CBS scheduler which does not include the following features:

  • Ability to attach more than one task to a Server;
  • Budget ( allowed computation time ) replenishment when a task exceeded its previous budget;
  • The served task is assigned with the ongoing server's priority.

This ticket presents a new CBS version where all the rules described by Abeni and Buttazzo are correctly implemented. This new version differs from the original CBS implementation on the following aspects:

  1. A server can now serve several tasks;
  2. When a served task exceeds its reserved capacity, its budget is replenished and the server's deadline updated and assigned as the new task priority;
  3. The callback function is removed due to the modification performed on the CBS behavior when a served task exceeds its reserved computational time;
  4. A task is killed when detached from a server since this new version only allows soft real-time tasks to run under Reservation-Based Context.

New Test Cases were developed and are directly included in the patch that will soon be attached.

Change History (1)

comment:1 Changed on May 11, 2019 at 4:59:20 PM by jollp

Cc: jollp@… added
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