Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-23 Thread Paul E. McKenney
On Thu, Aug 23, 2012 at 12:42:11PM +0200, Frederic Weisbecker wrote: > On Wed, Aug 22, 2012 at 12:01:09PM -0700, Paul E. McKenney wrote: > > > The current code is preemptable, at least it appears so because it calls > > > schedule() directly. And if I call rcu_idle_enter() in a preemptable > > > s

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-23 Thread Frederic Weisbecker
On Thu, Aug 23, 2012 at 09:32:18PM +1200, Michael Cree wrote: > On 23/08/12 04:23, Frederic Weisbecker wrote: > > In the old times, the whole idle task was considered > > as an RCU quiescent state. But as RCU became more and > > more successful overtime, some RCU read side critical > > section have

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-23 Thread Frederic Weisbecker
On Wed, Aug 22, 2012 at 12:01:09PM -0700, Paul E. McKenney wrote: > > The current code is preemptable, at least it appears so because it calls > > schedule() directly. And if I call rcu_idle_enter() in a preemptable > > section, > > I'm in trouble because I'll schedule while in extended QS. > > >

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-23 Thread Michael Cree
On 23/08/12 04:23, Frederic Weisbecker wrote: > In the old times, the whole idle task was considered > as an RCU quiescent state. But as RCU became more and > more successful overtime, some RCU read side critical > section have been added even in the code of some > architectures idle tasks, for tra

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-22 Thread Paul E. McKenney
On Wed, Aug 22, 2012 at 07:35:45PM +0200, Frederic Weisbecker wrote: > On Wed, Aug 22, 2012 at 10:19:30AM -0700, Paul E. McKenney wrote: > > On Wed, Aug 22, 2012 at 06:23:39PM +0200, Frederic Weisbecker wrote: > > > In the old times, the whole idle task was considered > > > as an RCU quiescent stat

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-22 Thread Frederic Weisbecker
On Wed, Aug 22, 2012 at 10:19:30AM -0700, Paul E. McKenney wrote: > On Wed, Aug 22, 2012 at 06:23:39PM +0200, Frederic Weisbecker wrote: > > In the old times, the whole idle task was considered > > as an RCU quiescent state. But as RCU became more and > > more successful overtime, some RCU read sid

Re: [PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-22 Thread Paul E. McKenney
On Wed, Aug 22, 2012 at 06:23:39PM +0200, Frederic Weisbecker wrote: > In the old times, the whole idle task was considered > as an RCU quiescent state. But as RCU became more and > more successful overtime, some RCU read side critical > section have been added even in the code of some > architectu

[PATCH 01/10] alpha: Add missing RCU idle APIs on idle loop

2012-08-22 Thread Frederic Weisbecker
In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu