Re: [BUG]locking/rwsem: only clean RWSEM_FLAG_HANDOFF when already set

From: Peter Zijlstra
Date: Thu Nov 11 2021 - 16:38:31 EST


On Thu, Nov 11, 2021 at 04:01:16PM -0500, Waiman Long wrote:

> > > + if (has_handoff || (!waiter->rt_task &&
> > > + !time_after(jiffies, waiter->timeout)))
> >
> > Does ->rt_task really help over rt_task(current) ? I suppose there's an
> > argument for locality, but that should be pretty much it, no?
> Waiting for the timeout may introduce too much latency for RT task. That is
> the only reason I am doing it. I can take it out if you think it is not
> necessary.

I meant simply calling rt_task(waiter->task) here, instead of mucking about
with the extra variable.