Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT") breaks boot

From	Rob Landley <rob@landley.net>
Newsgroups	linux.kernel
Subject	Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT") breaks boot
Date	2017-09-13 04:50 +0200
Message-ID	<up5Ut-1pM-9@gated-at.bofh.it> (permalink)
References	(2 earlier) <tKm6t-6oT-5@gated-at.bofh.it> <tKm6t-6oT-3@gated-at.bofh.it> <tKUhQ-4zw-11@gated-at.bofh.it> <uok9b-2JR-7@gated-at.bofh.it> <uovnY-2FY-17@gated-at.bofh.it>
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On 09/11/2017 06:45 AM, Petr Mladek wrote:
>> Except for the second printk line: If you boot with rdinit=/bin/hush
>> then the first time you mount -t devtmpfs /dev /dev after boot (with
>> CONFIG_DEVTMPFS_MOUNT already having mounted it), you get the 0 return
>> value but the last printk() doesn't output? The second and later times
>> you repeat it, both printk() lines are output.
>>
>> What's up with printk?
>>
>> (I added the second printk because the _first_ one wasn't outputting
>> that first time. Something is happening to flush the printk() queue
>> instead of writing it out?
> 
> You need to add "\n" at the end of the line. Otherwise, it expects
> that the message would continue and puts it into a cont buffer.
> The buffer is flushed only when another non-continuous message
> is added.

Ah. The next one flushes the previous one, meaning when I repeat the
command I get the output I expected the second time but I'm seeing the
_previous_ instance of it, not the current one.

> This problem is more visible since the commit 5c2992ee7fd8a29d0412
> ("printk: remove console flushing special cases for partial buffered
> lines").

Gotcha. My bad.

Thanks,

Rob

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Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT")  breaks boot Rob Landley <rob@landley.net> - 2017-09-11 01:50 +0200
  Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT")  breaks boot Petr Mladek <pmladek@suse.com> - 2017-09-11 13:50 +0200
    Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT")  breaks boot Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-12 02:50 +0200
    Re: Patch 0727d35de ("Make initramfs honor CONFIG_DEVTMPFS_MOUNT")  breaks boot Rob Landley <rob@landley.net> - 2017-09-13 04:50 +0200

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