Boot-up Time Delay Taxonomy
Note: This page is under construction
The goal of the taxonomy is to organize the different delays into categories based on (at least) 3 different attributes:
- boot phase - where boot phase is one of: firmware, kernel, user space
- magnitude - number microseconds
- type of delay - where type is one of: systemic, hardware, busy-wait
We probably also need some indication of the hardware and software running (so, some meta-data about the system), and whether this particular type of delay was avoidable or reducible (and by how much).
(delay type is weird. I need to think about this more - Tim)
Taxonomy Table
| Boot Phase | Type | Magnitude | Delay |
|---|---|---|---|
| firmware | hardware | 1-8 seconds | hard disk spin-up |
Process
Stuff in this section has to do with discussion and decisions about this page and the processes for creating the page, collaborating on it, etc.
Ed Chong and Tim Bird are currently working on this.
To do
- (done) Have a call to discuss goals, strategy, processes
- (done) Need to define a reference use case (automotive)
- Ed Chong to create a starting document
Resources
- Data from talks at OSSNA/ELC 2025
- Test results (like from grab-boot-data.sh)
- Centos Automotive boot time page: https://docs.centos.org/automotive-sig-documentation/performance/boot_time_optimization