Re: printk loglevel policy?

[David Howells]

Keith Owens <kaos@xxxxxxxxxx> wrote:

> >That kind of garbled output has been known to happen, but
> >the <console_sem> is supposed to prevent that (along with
> >zap_locks() in kernel/printk.c).
> 
> Using multiple calls to printk to print a single line has always been
> subject to the possibility of interleaving on SMP.  We just live with the
> risk. Printing a complete line in a single call to printk is protected by
> various locks.  Print a line in multiple calls is not protected.  If it
> bothers you that much, build up the line in a local buffer then call printk
> once.

The oops writer breaks the locks. It's _really_ annoying when oopses happen
simultaneously on separate CPUs - the oops reports end up interleaved
char-by-char.

My patch serialised oops writing.

David
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