Re: [PATCH 4/7] ARM: oprofile: Move non-ARM code into separate init/exit

[Paul Mundt <lethal@linux-sh.org>]

On Wed, Oct 06, 2010 at 08:44:07PM +0200, Robert Richter wrote:
> On 06.10.10 14:23:17, Grant Likely wrote:
> > >> diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
> > >> index b336cd9..76d97a5 100644
> > >> --- a/drivers/oprofile/oprof.c
> > >> +++ b/drivers/oprofile/oprof.c
> > >> @@ -252,6 +252,8 @@ static int __init oprofile_init(void)
> > >> ?{
> > >> ? ? ? int err;
> > >>
> > >> + ? ? memset(&oprofile_ops, 0, sizeof(struct oprofile_operations));
> > >> +
> > >
> > > Yes, this looks much better. Thanks Paul.
> > 
> > oprofile_ops is allocated in bss and so is already zeroed.  No need to
> > do it explicitly.
> 
> Before oprofile_arch_init() it isn't necessarily needed, but we should
> definitely add it before oprofile_timer_init(). For code readability I
> would rather tend to let the first in too.
> 
No, it was intentionally not added in between because architectures could
set a backtrace op even if they had no actual counter information to plug
in. oprofile_timer_init() is pretty careful to clear out all of the
unused fields manually, while leaving the backtrace setting untouched.

sh, ia64, and s390 all depend on this behaviour.