Hi again,
On 25.09.2020 21:08, Marek Szyprowski wrote:
> Hi John,
>
> On 14.09.2020 14:33, John Ogness wrote:
>> Use the record extending feature of the ringbuffer to implement
>> continuous messages. This preserves the existing continuous message
>> behavior.
>>
>> Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
>> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
>
> This patch landed recently in linux-next as commit f5f022e53b87
> ("printk: reimplement log_cont using record extension"). I've noticed
> that it causes a regression on my test system (ARM 32bit Samsung
> Exynos 4412-based Trats2 board). The messages are printed correctly on
> the serial console during boot, but then when I run 'dmesg' command,
> the log is truncated.
>
> Here is are the last lines of the dmesg log after this patch:
>
> [ 6.649018] Waiting 2 sec before mounting root device...
> [ 6.766423] dwc2 12480000.hsotg: new device is high-speed
> [ 6.845290] dwc2 12480000.hsotg: new device is high-speed
> [ 6.914217] dwc2 12480000.hsotg: new address 51
> [ 8.710351] RAMDISK: squashfs filesystem found at block 0
>
> The corresponding dmesg lines before applying this patch:
>
> [ 8.864320] RAMDISK: squashfs filesystem found at block 0
> [ 8.868410] RAMDISK: Loading 37692KiB [1 disk] into ram disk... /
> [ 9.071670] /
> [ 9.262498] /
> [ 9.540711] /
> [ 9.818031] done.
> [ 10.660074] VFS: Mounted root (squashfs filesystem) readonly on
> device 1:0.
> [ 10.739525] EXT4-fs (mmcblk0p1): INFO: recovery required on
> readonly filesystem
> [ 10.745347] EXT4-fs (mmcblk0p1): write access will be enabled
> during recovery
> [ 10.861129] EXT4-fs (mmcblk0p1): recovery complete
> [ 10.878150] EXT4-fs (mmcblk0p1): mounted filesystem with ordered
> data mode. Opts: (null)
> [ 10.881811] VFS: Mounted root (ext4 filesystem) readonly on device
> 179:49.
> [ 10.889858] Trying to move old root to /initrd ...
> [ 10.895192] okay
> [ 10.914411] devtmpfs: mounted
> [ 10.925087] Freeing unused kernel memory: 1024K
> [ 10.933222] Run /sbin/init as init process
> [ 10.941723] with arguments:
> [ 10.949890] /sbin/init
> [ 10.949900] with environment:
> [ 10.949909] HOME=/
> [ 10.949917] TERM=linux
> [ 12.415991] random: systemd-udevd: uninitialized urandom read (16
> bytes read)
> [ 12.425361] random: systemd-udevd: uninitialized urandom read (16
> bytes read)
> [ 12.438578] random: systemd-udevd: uninitialized urandom read (16
> bytes read)
>
> ...
>
> I can provide a complete logs if that helps.
One more information - this issue happens only if the kernel is compiled
from exynos_defconfig. If use multi_v7_defconfig, the dmesg works fine
on that board. exynos_defconfig has quite a lots of debugging options
enabled...
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
