Re: printk loglevel policy?

[Jim Nelson]

Randy.Dunlap wrote:
> Keith Owens wrote:
>
> > On Sun, 02 Jan 2005 13:41:34 -0800, "Randy.Dunlap" <rddunlap@xxxxxxxx> 
> > wrote:
> >
> > > Jim Nelson wrote:
> > >
> > > > Or does printk() do some tracking that I didn't see as to where in 
> > > > the kernel the strings are coming from?
> > >
> > >
> > > 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.
>
>
> True, I was thinking about the single line case, which I
> have seen garbled/mixed in the past (on SMP).  Hopefully
> that one is fixed.

Okay, that answered my question.  Is is frowned upon to use strncat/strcat in the 
kernel?  I have yet to see any use of them outside of the definition in 
lib/string.c.  It would seem to be faster (less potential contention for the 
printk locks).
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