Re: [RFC][PATCHv6 00/12] printk: introduce printing kernel thread

Sergey Senozhatsky
2017-12-19T01:03:21Z

On (12/18/17 12:46), Steven Rostedt wrote:
> On Mon, 18 Dec 2017 15:13:53 +0100
> Petr Mladek <pmladek@suse.com> wrote:
>
> > One question is if we really want to rely on offloading in
> > this case. What if this is printed to debug some stalled
> > system.
>
> Correct, and this is what I call when debugging hard lockups, and I do
> it from NMI. Which the new NMI code prevents all the data I want to
> print to come out to console.
>
> I had to create a really huge buffer to print it.
>
> show_state_filter() is not a normal printk() call. It is used for
> debugging. Not a very good example of issues that happen on production
> systems. If anything, this should be disabled on a production system.
>
> Let's just add my patch (I'll respin it if it needs it), and send it
> off into the wild. Let's see if there's still reports of issues, and
> then come back to solutions. Because, really, I'm still not convinced
> that there's anything out there that needs much more "fixing" of
> printk().

... do you guys read my emails? which part of the traces I have provided
suggests that there is any improvement?

-ss