COMP 3000 Essay 2 2010 Question 3

3.FlexSC: Flexible System Call Scheduling with Exception-Less System Calls

Paper

The Title of the paper we will be analyzing is named "FlexSC: Flexible System Call Scheduling with Exception-Less System Calls". The authors of this paper consist of Livio Stores and Michael Stumm, both of which are from the University of Toronto. The paper can be viewed here, [1] for further details on specifics of the essay.

Background Concepts:

In order to fully understand the FlexSC paper, it is essential to understand the key concepts that are discussed within the paper. Here listed below, are the main concepts required to fully comprehend the paper.

A System Call is the gateway between the User Space and the Kernel Space. The User Space is not given direct access to the Kernel's services, for several reasons (one being security), hence System calls are the messengers between the User and Kernel Space.

Processor Exceptions:

Synchronous Execution Model(System call Interface) refers to the structure in which system calls specifically are managed in a serialized manner. Moreover, the synchronous model completes one system call at a time, and does not move onto the next system call until the previous system call is finished executing.

System Call Pollution:

Mode Switches:

System Call Batching is the concept of batching (i.e.)grouping) system calls together. This idea is very similar to the counterpart of system calls in a sequential sequence. Groups are formed of system calls after the idea of batching has occurred instead of the initial individual system calls in a sequence.