Linux Device Drivers Development

Why delay writing data to disk?

There are essentially two reasons for that:

• Better use of the disk characteristics; this is efficiency
• Allows the application to continue immediately after a write; this is performance

For example, delaying disk access and processing data only when it reaches a certain size may improve disk performance and reduce wear leveling of eMMC (on embedded systems). Every chunk write is merged into a single and contiguous write operation. Additionally, written data is cached, allowing the process to return immediately so that any subsequent read will fetch the data from the cache, resulting in a more responsive program. Storage devices prefer a small number of large operations instead of several small operations. ...