Re: in_interrupt race

[Paul Mackerras]

george anzinger writes:

> > On Sat, 2002-04-20 at 06:27, Paul Mackerras wrote:
> > > One idea I had is to use a couple of bits in
> > > current_thread_info()->flags to indicate whether local_irq_count and
> > > local_bh_count are non-zero for the current cpu.  These bits could be
> > > tested safely without having to disable preemption.
> 
> Preemption lock is implied by either of these being != 0, so this seems
> consistant, but why not the whole counter?

Putting local_bh_count in the thread_info struct is easy and I have
done that locally here.

Putting local_irq_count in the thread_info struct means we would have
to do irqs_running() differently.  There is a brlock allocated for
BR_GLOBALIRQ_LOCK, which is used on some architectures.  Using that
would probably help.

Paul.