Re: [RFC][PATCH] printk: increase devkmsg write() ratelimit

From: Peter Zijlstra
Date: Tue Dec 18 2018 - 12:21:20 EST


On Wed, Dec 19, 2018 at 01:52:17AM +0900, Sergey Senozhatsky wrote:
> On (12/18/18 16:24), Borislav Petkov wrote:
> > On Wed, Dec 19, 2018 at 12:14:55AM +0900, Sergey Senozhatsky wrote:
> > > Right, but unlike log_buf_len, devkmsg is a bit close to a "binary" knob:
> > > either all messages or none;
> >
> > ... which is perfectly fine for a debugging session.
>
> But devkmsg ratelimits systemd errors, so one does not even know that
> "some debugging is required". For instance from my x86 box:
>
> Unmounting /home...
> [..]
> home.mount: Mount process exited, code=exited status=32
> Failed unmounting /home.
>
> I don't want to debug systemd, I want to know that something didn't
> work out. 10 messages max and 5 seconds interval looks a bit too strict.

Again, complain to system-doofus for printing so much crap to somewhere
it should not print to begin with.