| Number | Macro | Log Level | Description | Equivalent |
|---|---|---|---|---|
| 0 | pr_emerg | Emergency | System is unusable. | KERN_EMERG |
| 1 | pr_alert | Alert | Action must be taken immediately. | KERN_ALERT |
| 2 | pr_crit | Critical | Critical conditions. | KERN_CRIT |
| 3 | pr_err | Error | Error conditions. | KERN_ERR |
| 4 | pr_warn | Warning | Warning conditions. | KERN_WARNING |
| 5 | pr_notice | Notice | Normal but significant condition. | KERN_NOTICE |
| 6 | pr_info | Informational | Informational messages. | KERN_INFO |
| 7 | pr_debug | Debug | Debugging messages. | KERN_DEBUG |
- The number corresponds to the log level used by the Linux kernel, with lower numbers indicating higher severity.
- For example, if the log level is set to
4(Warning), only messages frompr_emergtopr_warnwill appear in the system logs. Default log level is generally set to 6.