Re: CONFIG_PRINTK_TIME woes

Andrew Morton
2005-08-21T09:34:17Z

Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> Andrew Morton wrote:
> > Andrew Morton <akpm@osdl.org> wrote:
> >
> >>How about we give each arch a printk_clock()?
> >
> >
> > Which might be as simple as this..
> >
> >
>
> sched_clock() shouldn't really be taken outside kernel/sched.c,
> especially for things like this.
>
> It actually has some fundamental problems even in its current
> use in the scheduler (which need to be fixed). But basically it
> is a very nasty interface with a rather tenuous relationship to
> time.

yup.

> Why not use something like do_gettimeofday? (or I'm sure one
> of our time keepers can suggest the right thing to use).

do_gettimeofday() takes locks, so a) we can't do printk from inside it and
b) if you do a printk-from-interupt and the interrupted code was running
do_gettimeofday(), deadlock.