Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Fri, Oct 06, 2017 at 10:32:19AM +0200, Peter Zijlstra wrote: > > AFAIU the scheduler rq->lock is held while preemption is disabled. > > synchronize_sched() is used here to ensure that all pre-existing > > preempt-off critical sections have completed. > > > > So saying that we use

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Fri, Oct 6, 2017 at 12:02 AM, Andrea Parri wrote: > On Thu, Oct 05, 2017 at 04:02:06PM +, Mathieu Desnoyers wrote: >> - On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: >> >> > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Thu, Oct 05, 2017 at 04:02:06PM +, Mathieu Desnoyers wrote: > - On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: > > > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: > >> diff --git a/arch/powerpc/kernel/membarrier.c > >>

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On 10/05/2017 07:23 AM, Nicholas Piggin wrote: On Wed, 4 Oct 2017 14:37:53 -0700 "Paul E. McKenney" wrote: From: Mathieu Desnoyers Provide a new command allowing processes to register their intent to use the private expedited

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

> AFAIU the scheduler rq->lock is held while preemption is disabled. > synchronize_sched() is used here to ensure that all pre-existing > preempt-off critical sections have completed. > > So saying that we use synchronize_sched() to synchronize with rq->lock > would be stretching the truth a bit.

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Thu, 5 Oct 2017 22:19:15 + (UTC) Mathieu Desnoyers wrote: > AFAIU the scheduler rq->lock is held while preemption is disabled. > synchronize_sched() is used here to ensure that all pre-existing > preempt-off critical sections have completed. > > So saying

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 6:02 PM, Andrea Parri parri.and...@gmail.com wrote: > On Thu, Oct 05, 2017 at 04:02:06PM +, Mathieu Desnoyers wrote: >> - On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: >> >> > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 12:21 PM, Peter Zijlstra pet...@infradead.org wrote: > On Thu, Oct 05, 2017 at 04:02:06PM +, Mathieu Desnoyers wrote: >> - On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: >> >> > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Thu, Oct 05, 2017 at 04:02:06PM +, Mathieu Desnoyers wrote: > - On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: > > > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: > >> diff --git a/arch/powerpc/kernel/membarrier.c > >>

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 8:24 AM, Peter Zijlstra pet...@infradead.org wrote: > On Thu, Oct 05, 2017 at 02:12:50PM +0200, Peter Zijlstra wrote: >> On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: >> > diff --git a/arch/powerpc/kernel/membarrier.c >> >

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 8:12 AM, Peter Zijlstra pet...@infradead.org wrote: > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: >> diff --git a/arch/powerpc/kernel/membarrier.c >> b/arch/powerpc/kernel/membarrier.c >> new file mode 100644 >> index ..b0d79a5f5981 >>

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 8:22 AM, Avi Kivity a...@scylladb.com wrote: > On 10/05/2017 07:23 AM, Nicholas Piggin wrote: >> On Wed, 4 Oct 2017 14:37:53 -0700 >> "Paul E. McKenney" wrote: >> >>> From: Mathieu Desnoyers >>> >>> Provide a

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

- On Oct 5, 2017, at 12:23 AM, Nicholas Piggin npig...@gmail.com wrote: > On Wed, 4 Oct 2017 14:37:53 -0700 > "Paul E. McKenney" wrote: > >> From: Mathieu Desnoyers >> >> Provide a new command allowing processes to register

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Thu, Oct 05, 2017 at 02:12:50PM +0200, Peter Zijlstra wrote: > On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: > > diff --git a/arch/powerpc/kernel/membarrier.c > > b/arch/powerpc/kernel/membarrier.c > > new file mode 100644 > > index ..b0d79a5f5981 > > ---

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Wed, Oct 04, 2017 at 02:37:53PM -0700, Paul E. McKenney wrote: > diff --git a/arch/powerpc/kernel/membarrier.c > b/arch/powerpc/kernel/membarrier.c > new file mode 100644 > index ..b0d79a5f5981 > --- /dev/null > +++ b/arch/powerpc/kernel/membarrier.c > @@ -0,0 +1,45 @@ > +void

Re: [PATCH tip/core/rcu 1/3] membarrier: Provide register expedited private command

On Wed, 4 Oct 2017 14:37:53 -0700 "Paul E. McKenney" wrote: > From: Mathieu Desnoyers > > Provide a new command allowing processes to register their intent to use > the private expedited command. > > This allows PowerPC to skip the