Re: [PATCH v2 01/12] sched: Simplify INIT_PREEMPT_COUNT

From: Frederic Weisbecker
Date: Thu Oct 01 2015 - 09:25:55 EST


On Wed, Sep 30, 2015 at 09:10:36AM +0200, Peter Zijlstra wrote:
> As per commit d86ee4809d03 ("sched: optimize cond_resched()") we need
> PREEMPT_ACTIVE to avoid cond_resched() from working before the
> scheduler is setup.
>
> However, keeping preemption disabled should do the same thing already,
> making the PREEMPT_ACTIVE part entirely redundant.
>
> The only complication is !PREEMPT_COUNT kernels, where
> PREEMPT_DISABLED ends up being 0. Instead we use an unconditional
> PREEMPT_OFFSET to set preempt_count() even on !PREEMPT_COUNT kernels.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>

Reviewed-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/