SWAG >> Cloning in the Linux SCSI drivers

Clones in the Linux SCSI drivers

It has been long noticed that drivers in the Linux kernel has higher clone ratio,especially within the SCSI (Small Computer Systems Interface) drivers. The SCSI subsystem in the Linux kernel is organized as a three-level system where upper- and mid-level are primarily interfaces while lower-level comprises of hardware-specific drivers ususally developed and contributed by different hardware vendors. Previous study speculated that the large number of similar drivers could be the cause of high clone ratio within the SCSI subsystem yet this notion is never validated.

In this study, we conduct a longitudinal research on clones in the SCSI subsystem and attemp to address the following quesions:

1. Do clones within the three architectural levels differ quantitatively?

2. How do clones in the SCSI subsystem evolve between versions and over time?

3. Can cloning be used as an effective predictor of hardware similarity?