lkml.org 
[lkml]   [2013]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/2] ipvs: Use cond_resched_rcu_lock() helper when dumping connections

Hello,

On Sat, 27 Apr 2013, Paul E. McKenney wrote:

> On Sat, Apr 27, 2013 at 02:32:48PM +0300, Julian Anastasov wrote:
> >
> > So, I assume, to help realtime kernels and rcu_barrier
> > it is not a good idea to guard rcu_read_unlock with checks.
> > I see that rcu_read_unlock will try to reschedule in the
> > !CONFIG_PREEMPT_RCU case (via preempt_enable), can we
> > use ifdefs to avoid double TIF_NEED_RESCHED check?:
> >
> > rcu_read_unlock();
> > #if !defined(CONFIG_PREEMPT) || defined(CONFIG_PREEMPT_RCU)
>
> I would instead suggest something like:
>
> #ifndef CONFIG_PREEMPT_RCU
>
> But yes, in the CONFIG_PREEMPT_RCU case, the cond_resched() is not
> needed.

Hm, is this correct? If I follow the ifdefs
preempt_schedule is called when CONFIG_PREEMPT is
defined _and_ CONFIG_PREEMPT_RCU is not defined.
Your example for CONFIG_PREEMPT_RCU is the opposite to this?

> Thanx, Paul
>
> > cond_resched();
> > #endif
> > rcu_read_lock();

Regards

--
Julian Anastasov <ja@ssi.bg>


\
 
 \ /
  Last update: 2013-04-29 23:21    [W:0.089 / U:0.500 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site