Re: Event logging vs enhancing printk

Martin J. Bligh
2002-04-09T02:15:48Z

> Ah. Yes, that will definitely happen. We only have atomicity
> at the level of a single printk call.
>
> It would be feasible to introduce additional locking so that
> multiple printks can be made atomic. This should be resisted
> though - printk needs to be really robust, and needs to have
> a good chance of working even when the machine is having hysterics.
> It's already rather complex.
>
> For the rare cases which you cite we can use a local staging
> buffer and sprintf, or just live with it, I suspect.

Right - what I'm proposing would be a generic equivalent of the
local staging buffer and sprintf - basically just a little wrapper
that does this for you, keeping a per task buffer somewhere.

The reason I want to do it like this, rather than what you suggest,
is that there are over 5000 of these "rare cases" of a printk without
a newline, according to the IBM RAS group's code search ;-) I don't
fancy changing that for 5000 instances (obviously some of those are
grouped together, but the count is definitely non-trivial). I'd
attach the report they sent me, but it's 657K long ;-)

M.