Re: [PATCH 3/9] sched/hotplug: Ensure only per-cpu kthreads run during hotplug

[Peter Zijlstra]

On Fri, Sep 25, 2020 at 06:38:50PM +0200, Dietmar Eggemann wrote:
> On 21/09/2020 18:36, Peter Zijlstra wrote:
> 
> [...]
> 
> > This replaces the unlikely(rq->balance_callbacks) test at the tail of
> > context_switch with an unlikely(rq->balance_work), the fast path is
> 
> While looking for why BALANCE_WORK is needed:
> 
> Shouldn't this be unlikely(rq->balance_callback) and
> unlikely(rq->balance_flags)?

But then we have two loads in the fastpath..