Re: [PATCH v3] printk: Have printk() never buffer its data

Kay Sievers
2012-07-05T11:47:48Z

On Thu, Jul 5, 2012 at 12:20 PM, Michael Neuling <mikey@neuling.org> wrote:

> I can only make 2) happen on SMP. It's when the second CPU is coming up
> and it's printing something. The first CPU isn't printing anything at
> this stage (there is no garbled console here) so I don't think it's a
> race. I see it consistently in show_regs(). Every printk without a
> newline. ie I get this:
> ---
> NIP: c000000000048164 LR: c000000000048160 CTR: 0000000000000000
> REGS: c00000007e59fb50 TRAP: 0700 Tainted: G W (3.5.0-rc5-mikey)
> MSR: 9000000000021032
> <
> SF
> ,HV
> ,ME
> ,IR
> ,DR
> ,RI
>>
> CR: 28000042 XER: 22000000
> SOFTE: 0
> CFAR: c0000000007402f8
> TASK = c00000007e56bb40[0] 'swapper/1' THREAD: c00000007e59c000
> CPU: 1
> ---
>
> It's consistent for printks without newlines in show_regs(). MSR
> through to XER should all be on the same line.

I see. Something to fix then, I'll have a look.

Does this happen only very early during bootup, or also later when the
box fully initialized?

The output of 'dmesg' later looks always correct, right?

Thanks,
Kay