Re: [PATCH 2/4] sched: Isolate preempt counting in its own config option

Peter Zijlstra
2011-06-08T19:47:25Z

On Wed, 2011-06-08 at 19:48 +0200, Frederic Weisbecker wrote:
>
> Create a new CONFIG_PREEMPT_COUNT that handles the inc/dec
> of preempt count offset independently. So that the offset
> can be updated by preempt_disable() and preempt_enable()
> even without the need for CONFIG_PREEMPT beeing set.
>
> This prepares to make CONFIG_DEBUG_SPINLOCK_SLEEP working
> with !CONFIG_PREEMPT where it currently doesn't detect
> code that sleeps inside explicit preemption disabled
> sections.

The last time this got proposed it got shot down due to the extra
inc/dec stuff all over the place increasing overhead significantly.