Re: [PATCH] printk: Don't discard earlier unprinted messages to make space

[David Howells <dhowells@redhat.com>]

Petr Mladek <pmladek@suse.com> wrote:

> I would expect that the first few messages are printed to the console
> before the buffer is wrapped. IMHO, in many cases, you are interested
> into the final messages that describe why the system went down.

The last message might tell you that the machine panicked because the NMI
handler triggered due to a spinlocked section taking too long or something.
This doesn't help if the oops that caused the spinlock to remain held or
whatever gets discarded from the buffer due to several intervening complaints
that result secondarily from the initial oops.

> If there is no time to print them, you want to have them in the crash dump
> (ring buffer) at least.

But not at the expense of discarding the first oops report.  *That* one is the
most important.

Perhaps things could be arranged such that messages *can* be discarded from
the front of the buffer *provided* they are not oops messages.

David