与有关 kern.log 和 syslog 中无法控制的膨胀的其他问题类似，但就我而言，我无法弄清楚内核中是什么原因导致了它，因为我无法识别该过程并且我对此进行的谷歌搜索也没有太大帮助。
两个独立的 raspberry pi 4 运行 Ubuntu 20.04 几个星期。一切都很好。昨晚，我运行了标准的 apt 升级，然后我的 kern.log 和 syslog 开始以每小时约 0.5-1 Gb 的速度不受控制地增长，现在我只能一遍又一遍地截断它们，同时试图找出填满内核日志的是什么。这是对 kern.log 文件进行跟踪的输出。它只是一遍又一遍地重复，每秒 100 次。
May 23 07:43:03 raspi2 kernel: [12298.982475] WARNING: CPU: 0 PID: 4409 at drivers/mmc/host/sdhci.c:1101 sdhci_prepare_data+0x3dc/0x7b0
May 23 07:43:03 raspi2 kernel: [12298.982478] Modules linked in: binfmt_misc iptable_filter bpfilter dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua btsdio bluetooth ecdh_generic ecc brcmfmac bcm2835_v4l2(CE) brcmutil bcm2835_mmal_vchiq(CE) videobuf2_vmalloc videobuf2_memops snd_bcm2835(CE) videobuf2_v4l2 cfg80211 videobuf2_common snd_pcm videodev snd_timer mc snd raspberrypi_hwmon vc_sm_cma(CE) rpivid_mem uio_pdrv_genirq uio sch_fq_codel drm ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor xor_neon raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_ce spidev phy_generic ses enclosure scsi_transport_sas uas usb_storage aes_neon_bs aes_neon_blk crypto_simd cryptd
May 23 07:43:03 raspi2 kernel: [12298.982532] CPU: 0 PID: 4409 Comm: kworker/0:0H Tainted: G WC E 5.4.0-1011-raspi #11-Ubuntu
May 23 07:43:03 raspi2 kernel: [12298.982533] Hardware name: Raspberry Pi 4 Model B Rev 1.2 (DT)
May 23 07:43:03 raspi2 kernel: [12298.982545] Workqueue: kblockd blk_mq_run_work_fn
May 23 07:43:03 raspi2 kernel: [12298.982551] pstate: a0400085 (NzCv daIf +PAN -UAO)
May 23 07:43:03 raspi2 kernel: [12298.982553] pc : sdhci_prepare_data+0x3dc/0x7b0
May 23 07:43:03 raspi2 kernel: [12298.982556] lr : sdhci_prepare_data+0x2cc/0x7b0
May 23 07:43:03 raspi2 kernel: [12298.982557] sp : ffff80001156b9b0
May 23 07:43:03 raspi2 kernel: [12298.982558] x29: ffff80001156b9b0 x28: ffff0000eb62ec00
May 23 07:43:03 raspi2 kernel: [12298.982560] x27: 0000000000000002 x26: 0000000000000000
May 23 07:43:03 raspi2 kernel: [12298.982562] x25: ffff0000eb5e7000 x24: ffff0000eb5e7580
May 23 07:43:03 raspi2 kernel: [12298.982564] x23: 0000000000418958 x22: ffff0000eb06a158
May 23 07:43:03 raspi2 kernel: [12298.982566] x21: ffff0000277d0000 x20: ffff0000eb06a1d8
May 23 07:43:03 raspi2 kernel: [12298.982568] x19: ffff0000eb5e7580 x18: 0000000000000000
May 23 07:43:03 raspi2 kernel: [12298.982570] x17: 0000000000000000 x16: 0000000000000000
May 23 07:43:03 raspi2 kernel: [12298.982572] x15: 0000000000000000 x14: 622061756c615f68
May 23 07:43:03 raspi2 kernel: [12298.982574] x13: 645f697363732063 x12: 6d655f68645f6973
May 23 07:43:03 raspi2 kernel: [12298.982576] x11: 637320636164725f x10: 68645f6973637320
May 23 07:43:03 raspi2 kernel: [12298.982577] x9 : 6874617069746c75 x8 : 6d5f6d6420726574
May 23 07:43:03 raspi2 kernel: [12298.982579] x7 : 6c69667062207265 x6 : ffffcb8fd5209a44
May 23 07:43:03 raspi2 kernel: [12298.982581] x5 : ffffffffffffffff x4 : 0000000000000020
May 23 07:43:03 raspi2 kernel: [12298.982583] x3 : 0000000000000001 x2 : fffffe0003581300
May 23 07:43:03 raspi2 kernel: [12298.982585] x1 : fffffe0003581300 x0 : 00000000ffffffe4
May 23 07:43:03 raspi2 kernel: [12298.982588] Call trace:
May 23 07:43:03 raspi2 kernel: [12298.982591] sdhci_prepare_data+0x3dc/0x7b0
May 23 07:43:03 raspi2 kernel: [12298.982593] sdhci_send_command+0xe0/0x5f0
May 23 07:43:03 raspi2 kernel: [12298.982595] sdhci_request+0x110/0x150
May 23 07:43:03 raspi2 kernel: [12298.982599] __mmc_start_request+0x88/0x1a8
May 23 07:43:03 raspi2 kernel: [12298.982601] mmc_start_request+0x98/0xc0
May 23 07:43:03 raspi2 kernel: [12298.982603] mmc_blk_mq_issue_rq+0x30c/0x778
May 23 07:43:03 raspi2 kernel: [12298.982605] mmc_mq_queue_rq+0x14c/0x320
May 23 07:43:03 raspi2 kernel: [12298.982608] blk_mq_dispatch_rq_list+0xa4/0x5f8
May 23 07:43:03 raspi2 kernel: [12298.982612] blk_mq_do_dispatch_sched+0x68/0x108
May 23 07:43:03 raspi2 kernel: [12298.982614] blk_mq_sched_dispatch_requests+0x164/0x1c0
May 23 07:43:03 raspi2 kernel: [12298.982617] __blk_mq_run_hw_queue+0xfc/0x158
May 23 07:43:03 raspi2 kernel: [12298.982619] blk_mq_run_work_fn+0x28/0x38
May 23 07:43:03 raspi2 kernel: [12298.982622] process_one_work+0x1d0/0x430
May 23 07:43:03 raspi2 kernel: [12298.982624] worker_thread+0x54/0x4a0
May 23 07:43:03 raspi2 kernel: [12298.982628] kthread+0xfc/0x128
May 23 07:43:03 raspi2 kernel: [12298.982631] ret_from_fork+0x10/0x1c
May 23 07:43:03 raspi2 kernel: [12298.982634] ---[ end trace a7bb7a8fcc54873a ]---
一遍又一遍，直到日志填满磁盘。两个 pi 上的情况完全一样，我对它们所做的唯一更改是通过 apt upgrade 进行升级，如所述。
看起来像是 sdhci 的问题，但我无法弄清楚：a) 升级的哪一部分导致了这个问题的发生 [为什么这个问题现在才发生] 以及 b) 如何解决根本问题。
由于我的系统操作正常，我是否只需要告诉 rsyslog 忽略来自 sdhci 的消息？我实际上想修复这个问题，而不仅仅是在可行的情况下忽略。
谢谢！
答案1
我今天遇到了同样的问题（kern.log 增长很快；大约 2GB），并使用以下命令将内核降级到以前的版本：
从系统中删除1001版本：
apt remove linux-image-5.4.0-1011-raspi
重新安装先前版本的内核、模块和头文件：
apt-get install --reinstall linux-image-5.4.0-1008-raspi
apt-get install --reinstall linux-headers-5.4.0-1008-raspi
apt-get install --reinstall linux-modules-5.4.0-1008-raspi
我使用之前的内核版本成功重启了 PI4。下一步是将内核从更新中排除，直到问题得到解决：
apt-mark hold linux-image-5.4.0-1008-raspi
apt-mark hold linux-headers-5.4.0-1008-raspi
apt-mark hold linux-modules-5.4.0-1008-raspi
之后您可以删除未使用的内核版本：
apt remove linux-raspi-headers-5.4.0-1011
# after a reboot:
pi04:~/.ssh# uname -a
Linux pi04 5.4.0-1008-raspi #8-Ubuntu SMP Wed Apr 8 11:13:06 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux
# to clean up the system the 1011 headers and modules can be removed
apt remove linux-headers-5.4.0-1011-raspi
apt remove linux-modules-5.4.0-1011-raspi
从您的系统中。
我的系统安装历史：
Filename: /var/log/apt/history.log
Start-Date: 2020-05-22 09:51:29
Commandline: apt upgrade
Install: linux-headers-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-modules-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-image-5.4.0-1011-raspi:arm64 (5.4.0-1011.11, automatic), linux-raspi-headers-5.4.0-1011:arm64 (5.4.0-1011.11, automatic)
Upgrade: linux-raspi:arm64 (5.4.0.1008.8, 5.4.0.1011.11), linux-image-raspi:arm64 (5.4.0.1008.8, 5.4.0.1011.11), linux-headers-raspi:arm64 (5.4.0.1008.8, 5.4.0.1011.11)
End-Date: 2020-05-22 09:53:15
Start-Date: 2020-05-23 22:14:40
Commandline: apt remove linux-image-5.4.0-1011-raspi
Remove: linux-raspi:arm64 (5.4.0.1011.11), linux-image-raspi:arm64 (5.4.0.1011.11), linux-image-5.4.0-1011-raspi:arm64 (5.4.0-1011.11)
End-Date: 2020-05-23 22:14:59
Start-Date: 2020-05-23 22:15:38
Commandline: apt autoremove
Remove: linux-headers-raspi:arm64 (5.4.0.1011.11)
End-Date: 2020-05-23 22:15:38
Start-Date: 2020-05-23 22:23:43
Commandline: apt-get install --reinstall linux-image-5.4.0-1008-raspi
Reinstall: linux-image-5.4.0-1008-raspi:arm64 (5.4.0-1008.8)
End-Date: 2020-05-23 22:25:02
Start-Date: 2020-05-23 22:27:46
Commandline: apt-get install --reinstall linux-headers-5.4.0-1008-raspi
Reinstall: linux-headers-5.4.0-1008-raspi:arm64 (5.4.0-1008.8)
End-Date: 2020-05-23 22:27:57
Start-Date: 2020-05-23 22:28:35
Commandline: apt-get install --reinstall linux-modules-5.4.0-1008-raspi
Reinstall: linux-modules-5.4.0-1008-raspi:arm64 (5.4.0-1008.8)
End-Date: 2020-05-23 22:30:03
Start-Date: 2020-05-23 22:59:16
Commandline: apt remove linux-raspi-headers-5.4.0-1011
Remove: linux-headers-5.4.0-1011-raspi:arm64 (5.4.0-1011.11), linux-raspi-headers-5.4.0-1011:arm64 (5.4.0-1011.11)
End-Date: 2020-05-23 22:59:25