Use Old Kernel¶
Info
Post: 2021.07.28
最近几天，T460P 经常自动重启，而且往往重启前花屏，甚至今天带着电脑去找老板，也重启了两次。在 /var/crash 目录下能发现 crash 报告，但是并不知道怎么使用
drwxr-sr-x 2 root whoopsie 4096 Jul 22 20:10 202107222000/
drwxr-sr-x 2 root whoopsie 4096 Jul 23 05:40 202107230539/
drwxr-sr-x 2 root whoopsie 4096 Jul 23 08:54 202107230854/
drwxr-sr-x 2 root whoopsie 4096 Jul 24 14:23 202107241422/
drwxr-sr-x 2 root whoopsie 4096 Jul 26 09:03 202107260517/
drwxr-sr-x 2 root whoopsie 4096 Jul 27 09:26 202107270926/
drwxr-sr-x 2 root whoopsie 4096 Jul 27 23:09 202107272308/
drwxr-sr-x 2 root whoopsie 4096 Jul 28 09:41 202107280940/
drwxr-sr-x 2 root whoopsie 4096 Jul 28 09:44 202107280944/
drwxr-sr-x 2 root whoopsie 4096 Jul 28 10:14 202107281014/
drwxr-sr-x 2 root whoopsie 4096 Jul 28 11:05 202107281105/
drwxr-sr-x 2 root whoopsie 4096 Jul 28 11:48 202107281148/
-rw-r--r-- 1 kernoops whoopsie 2249 Jul 24 14:40 linux-image-4.15.0-151-generic.183202.crash
-rw-r----- 1 root whoopsie 34940 Jul 22 20:01 linux-image-4.15.0-151-generic-202107222000.crash
-rw-r----- 1 root whoopsie 29062 Jul 23 08:55 linux-image-4.15.0-151-generic-202107230854.crash
-rw-r----- 1 root whoopsie 34532 Jul 24 14:23 linux-image-4.15.0-151-generic-202107241422.crash
-rw-r----- 1 root whoopsie 35752 Jul 26 08:56 linux-image-4.15.0-151-generic-202107260517.crash
-rw-r--r-- 1 kernoops whoopsie 746 Jul 28 09:40 linux-image-4.15.0-151-generic.30586.crash
-rw-r--r-- 1 kernoops whoopsie 752 Jul 28 09:40 linux-image-4.15.0-151-generic.30735.crash
其中每个文件夹中有
$ ll 202107281148
total 109160
-rw------- 1 root whoopsie 78507 Jul 28 11:48 dmesg.202107281148
-rw------- 1 root whoopsie 111683440 Jul 28 11:48 dump.202107281148
联想下最近的操作，很有可能是通过 apt upgrade 更新了次内核，查看具体细节
$ vi /var/log/apt/history.log
Start-Date: 2021-07-21 20:46:59
Commandline: aptdaemon role='role-commit-packages' sender=':1.1117'
Install: linux-headers-4.15.0-151-generic:amd64 (4.15.0-151.157, automatic), linux-modules-4.15.0-151-generic:amd64 (4.15.0-151.157, automatic), linux-image-4.15.0-151-generic:amd64 (4.15.0-151.157, automatic), linux-modules-extra-4.15.0-151-generic:amd64 (4.15.0-151.157, automatic), linux-headers-4.15.0-151:amd64 (4.15.0-151.157, automatic)
Upgrade: libnvidia-gl-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-gl-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), linux-headers-generic:amd64 (4.15.0.147.134, 4.15.0.151.139), linux-libc-dev:amd64 (4.15.0-147.151, 4.15.0-151.157), linux-crashdump:amd64 (4.15.0.147.134, 4.15.0.151.139), libsystemd0:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), libsystemd0:i386 (237-3ubuntu10.48, 237-3ubuntu10.49), linux-image-generic:amd64 (4.15.0.147.134, 4.15.0.151.139), nvidia-driver-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), containerd:amd64 (1.5.2-0ubuntu1~18.04.1, 1.5.2-0ubuntu1~18.04.2), nvidia-kernel-source-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-fbc1-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-fbc1-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), nvidia-dkms-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), google-chrome-stable:amd64 (91.0.4472.164-1, 92.0.4515.107-1), nvidia-utils-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-decode-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-decode-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), udev:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), nvidia-kernel-common-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), typora:amd64 (0.10.11-1, 0.11.0-1), xserver-xorg-video-nvidia-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-encode-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-encode-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), nvidia-compute-utils-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), initramfs-tools-bin:amd64 (0.130ubuntu3.12, 0.130ubuntu3.13), linux-signed-generic:amd64 (4.15.0.147.134, 4.15.0.151.139), libudev1:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), libudev1:i386 (237-3ubuntu10.48, 237-3ubuntu10.49), libnvidia-ifr1-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-ifr1-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-common-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnss-myhostname:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), libnvidia-cfg1-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), systemd-sysv:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), libpam-systemd:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), systemd:amd64 (237-3ubuntu10.48, 237-3ubuntu10.49), libnvidia-extra-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), linux-generic:amd64 (4.15.0.147.134, 4.15.0.151.139), initramfs-tools-core:amd64 (0.130ubuntu3.12, 0.130ubuntu3.13), initramfs-tools:amd64 (0.130ubuntu3.12, 0.130ubuntu3.13), libnvidia-compute-460-server:amd64 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1), libnvidia-compute-460-server:i386 (460.73.01-0ubuntu0.18.04.1, 460.91.03-0ubuntu0.18.04.1)
End-Date: 2021-07-21 20:51:53
Start-Date: 2021-07-22 06:31:33
Commandline: /usr/bin/unattended-upgrade
Remove: linux-headers-4.15.0-144:amd64 (4.15.0-144.148), linux-headers-4.15.0-144-generic:amd64 (4.15.0-144.148)
End-Date: 2021-07-22 06:31:36
Tip
对于 .gz 的日志文件，可以使用 zcat 直接查看。
另外注意，file.gz 解压时默认不会保存原始文件，或者指定 gunzip -k 选项，或者
gunzip < file.gz > file
发现其更新时间恰恰在诸多 crash 的前一天。所以试图切换到老的内核版本。
注意到在启动时，第二个选项是 Advanced options for Ubuntu，点进去有若干个内核，我的是
4.15.0-151
4.15.0-151 (recovery mode)
4.15.0-147
4.15.0-147 (recovery mode)
选择 4.15.0-147，进去之后发现扩展屏幕无法识别，另外 Nvidia 也没有识别。于是试着重装 nvidia driver，这次选择的是 nvidia-driver-460-server，这也是此前使用的版本。
然后重启。
重启时注意还是要选择 4.15.0-147，不如默认进的还是 151。
中间误入了一次 151，结果还没登录就自动重启了，然后乖乖选择 147，但是这次还是没能识别 HDMI，不过 nvidia-smi 以及 nvidia-settings 都正常，xrandr 输出也是没有识别出显示屏。
2022-12-13
根据顶部状态栏发现，有时 GPU 无监控，再运行 nvidia-smi 报错
$ nvidia-smi
Failed to initialize NVML: Driver/library version mismatch
的讨论，最好的方式可能还是直接重启。
试着继续重启，这次竟然可以了！
后面在 nvidia-settings 中试了将 PRIME profiles 由 NVIDIA (performance mode) 改成 NVIDIA on-demand,然后重启，结果竟然进不去系统了，每次输入密码回车都要求重新输入密码。
原因很可能是 PRIME 的这一改动，于是进入 tty 模式，通过命令行改回来
# 查询当前选择
$ prime-select query
# 切换至 nvidia
$ prime-select nvidia
# 切换至 intel
$ prime-select intel
然后重启终于恢复正常。
注意现在每次重启都需要选择内核版本，一个自然想法是修改默认内核。参考 How Do I Change the Default Boot Kernel in Ubuntu?
将 /etc/default/grub 中 GRUB_DEFAULT 修改至 1>2，其中
1代表Advanced options for Ubuntu的顺序，因其在第二位，顺序从 0 算起，默认值就是 0>2代表在子目录下位于第 2 位（顺序从 0 算起，即第三个）
重启之前需要运行
$ sudo update-grub
重启之后可以看到自动选择了 1>2。
disable update of kernel¶
今天竟然又重启了，有点无法理解。第一次怀疑是温度过高，因为 syslog 中重启前的一条记录信息为
Device: /dev/sdc [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 60 to 61
然后第二次竟然发现 crash 报告竟然是 151，明明应该选择了第二个 147 呀。
$ ls /var/crash
linux-image-4.15.0-151-generic-202108070025.crash
linux-image-4.15.0-151-generic-202108071819.crash
重启时才发现竟然多了个 kernel 153！！于是第二个变成了 151，第三个才是 147。
虽然将启动选择再改成第三个应该也是可以的，但是万一以后又多了一个呢，顺序岂不又变了，所以更好的方法便是禁止 kernel 更新。另外将最新的 151 删掉。
- 删掉 kernel
查看安装 kernel 的完整名称，
$ dpkg -l | grep linux-image | grep "^ii"
然后进行删除
$ sudo apt purge linux-image-4.15.0-153-generic
再次重启就会发现第一项 153 消失了。
refer to Ubuntu 18.04 remove all unused old kernels
- 禁止 kernel 更新
参考 How to I prevent Ubuntu from kernel version upgrade and notification?
sudo apt-mark hold 4.15.0-147-generic
The resulting status is hi, where the first letter implies hold.
~$ dpkg -l | grep "4.15.0-147"
ii linux-headers-4.15.0-147 4.15.0-147.151 all Header files related to Linux kernel version 4.15.0
hi linux-headers-4.15.0-147-generic 4.15.0-147.151 amd64 Linux kernel headers for version 4.15.0 on 64 bit x86 SMP
hi linux-image-4.15.0-147-generic 4.15.0-147.151 amd64 Signed kernel image generic
hi linux-modules-4.15.0-147-generic 4.15.0-147.151 amd64 Linux kernel extra modules for version 4.15.0 on 64 bit x86 SMP
hi linux-modules-extra-4.15.0-147-generic 4.15.0-147.151 amd64 Linux kernel extra modules for version 4.15.0 on 64 bit x86 SMP
2022-06-13
However, currently the kernel is
~$ date
Mon 13 Jun 2022 04:17:43 PM CST
~$ uname -a
Linux weiya-ThinkPad-T460p 5.4.0-110-generic #124-Ubuntu SMP Thu Apr 14 19:46:19 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
so it is outdated to hold such kernel. To undo such operation,
$ sudo apt-mark unhold 4.15.0-147-generic
Then it will be removed if we perform autoclean
~$ sudo apt autoremove --purge
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
linux-headers-4.15.0-147* linux-headers-4.15.0-147-generic* linux-image-4.15.0-147-generic* linux-modules-4.15.0-147-generic* linux-modules-extra-4.15.0-147-generic*
Note that this command will still keep one old kernel, along with the currently running one . For example,
~$ dpkg -l | grep "linux-image" | grep '^ii'
ii linux-image-5.4.0-110-generic 5.4.0-110.124 amd64 Signed kernel image generic
ii linux-image-5.4.0-117-generic 5.4.0-117.132 amd64 Signed kernel image generic
ii linux-image-generic 5.4.0.117.120 amd64 Generic Linux kernel image
However, here is a warning,
Warning
dpkg: warning: while removing linux-modules-4.15.0-147-generic, directory ‘/lib/modules/4.15.0-147-generic’ not empty so not removed