Re: Re: printk meeting at LPC

From: Petr Mladek
Date: Mon Oct 07 2019 - 08:01:42 EST


On Fri 2019-10-04 09:48:24, Tony Asleson wrote:
> On 9/13/19 8:26 AM, John Ogness wrote:
> > 9. Support for printk dictionaries will be discontinued. I will look
> > into who is using this and why. If printk dictionaries are important for
> > you, speak up now!
>
> I think this functionality is important.
>
> I've been experimenting with a change which adds dictionary data to
> storage related printk messages so that a persistent durable id is
> associated with them for filtering, eg.
>
> $ journalctl -r _KERNEL_DURABLE_NAME=naa.0000000000bc614e
>
> This has the advantage that when the device attachment changes across
> reboots or detach/reattach cycles you can easily find its messages
> throughout it's recorded history.

Thanks for the pointers. I think that we will need to keep the
dictionaries then.

Just for explanation. We were not aware of this functionality when
it was discussed. The expectation was that this feature has never
been used in userspace. We were too optimistic ;-)

Best Regards,
Petr