如何解读Linux dmesg关键日志信息

dmesg（display message或者driver message）是Linux下一个用于显示内核启动信息和运行时状态的命令行工具。它从内核环形缓冲区中读取数据并显示在屏幕上。这些信息对于诊断硬件和软件问题非常有用。

以下是如何解读dmesg关键日志信息的一些建议：

1. 时间戳：每条日志信息前面都有一个时间戳，表示该事件发生的时间。这有助于了解事件发生的顺序。

2. 优先级：日志信息有不同的优先级，如[U]（未知）、[I]（信息）、[W]（警告）、[E]（错误）、[A]（警报）等。优先级有助于识别问题的严重性。

3. 内核模块：日志信息通常会显示涉及的内核模块名称，这有助于确定哪个模块可能存在问题。

4. 设备和驱动程序：日志信息通常会显示涉及的设备和驱动程序名称，这有助于确定哪个设备或驱动程序可能存在问题。

5. 错误代码和描述：日志信息通常会显示错误代码和相关描述，这有助于了解问题的具体原因。

以下是一些常见的dmesg日志信息示例及其解释：

• 莺歌燕舞，马到成功：这是一条表示系统正常启动的信息，意味着内核已经成功加载并运行。
• [ 0.000000] Initializing cgroup subsys cpuset：这是一条初始化cgroup子系统cpuset的信息，表示系统正在设置资源管理策略。
• [ 0.000000] Linux version 5.4.0-42-generic (buildd@lgw01-amd64-039) (gcc version 9.3.0 (Ubuntu 9.3.0-10ubuntu2)) #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020：这是一条显示Linux内核版本和构建信息的信息。
• [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.4.0-42-generic root=UUID=xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx ro quiet splash vt.handoff=7：这是一条显示系统启动命令行参数的信息。
• [ 0.000000] KERNEL supported cpus:：这是一条显示系统支持的CPU的信息。
• [ 0.000000] ACPI: Added _OSI(Module Device)
• [ 0.000000] ACPI: Added _OSI(Processor Device)
• [ 0.000000] ACPI: Added _OSI(3.0 _SCP Extensions)
• [ 0.000000] ACPI: Added _OSI(Processor Aggregator Device)
• [ 0.000000] ACPI: Added _OSI(Power Button)
• [ 0.000000] ACPI: Added _OSI(Video Device)
• [ 0.000000] ACPI: Added _OSI(9 _SCP Extensions)
• [ 0.000000] ACPI: Added _OSI(Processor Device)
• [ 0.000000] ACPI: Added _OSI(3.0 _SCP Extensions)
• [ 0.000000] ACPI: Added _OSI(Processor Aggregator Device)
• [ 0.000000] ACPI: Added _OSI(Power Button)
• [ 0.000000] ACPI: Added _OSI(Video Device)
• [ 0.000000] ACPI: Added _OSI(9 _SCP Extensions)
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Added _OSI(Processor Device)
• [ 0.000000] ACPI: Added _OSI(3.0 _SCP Extensions)
• [ 0.000000] ACPI: Added _OSI(Processor Aggregator Device)
• [ 0.000000] ACPI: Added _OSI(Power Button)
• [ 0.000000] ACPI: Added _OSI(Video Device)
• [ 0.000000] ACPI: Added _OSI(9 _SCP Extensions)
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• [ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code
• [ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**
• `[ 0.000000] ACPI: Enabled 3 blocks of fixed ACPI AML code**
• `[ 0.000000] ACPI: Executed 1 blocks of module-level executable AML code**