[GIT PULL] nohz: Move nohz kick out of scheduler IPI, v9

[GIT PULL] nohz: Move nohz kick out of scheduler IPI, v9

[Frederic Weisbecker]

Ingo,

Please pull the timers/nohz-irq-work-v7 branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	timers/nohz-irq-work-v7

It has been acked by Peterz.

--- Summary ---

This set moves the nohz kick, used to notify a full dynticks CPU when
events require tick rescheduling, out of the scheduler tick to a
dedicated IPI.

This debloats a bit the scheduler IPI from off-topic work that was
abusing that scheduler fast path for its convenient asynchronous
properties. Now the nohz kick uses irq work for its own needs.

Of course this implied quite some background infrastructure rework,
including:

* Clean up some irq work internals
* Implement remote irq work
* Implement nohz kick on top of remote irq work
* Move full dynticks timer enqueue notification to new kick
* Move multi-task notification to new kick
* Remove unecessary barriers on multi-task notification

Thanks,
	Frederic
---

Frederic Weisbecker (6):
      irq_work: Split raised and lazy lists
      irq_work: Implement remote queueing
      nohz: Support nohz full remote kick
      nohz: Switch to nohz full remote kick on timer enqueue
      nohz: Use nohz own full kick on 2nd task enqueue
      nohz: Use IPI implicit full barrier against rq->nr_running r/w


 include/linux/irq_work.h |  5 ++++
 include/linux/tick.h     |  9 +++++-
 kernel/irq_work.c        | 76 ++++++++++++++++++++++++++++++------------------
 kernel/sched/core.c      | 22 ++++++++------
 kernel/sched/sched.h     | 12 ++++++--
 kernel/smp.c             |  9 ++++++
 kernel/time/tick-sched.c | 10 ++++---
 7 files changed, 97 insertions(+), 46 deletions(-)

Re: [GIT PULL] nohz: Move nohz kick out of scheduler IPI, v9

[Ingo Molnar]

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> Ingo,
> 
> Please pull the timers/nohz-irq-work-v7 branch that can be found at:
> 
> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
> 	timers/nohz-irq-work-v7
> 
> It has been acked by Peterz.
> 
> --- Summary ---
> 
> This set moves the nohz kick, used to notify a full dynticks CPU when
> events require tick rescheduling, out of the scheduler tick to a
> dedicated IPI.
> 
> This debloats a bit the scheduler IPI from off-topic work that was
> abusing that scheduler fast path for its convenient asynchronous
> properties. Now the nohz kick uses irq work for its own needs.
> 
> Of course this implied quite some background infrastructure rework,
> including:
> 
> * Clean up some irq work internals
> * Implement remote irq work
> * Implement nohz kick on top of remote irq work
> * Move full dynticks timer enqueue notification to new kick
> * Move multi-task notification to new kick
> * Remove unecessary barriers on multi-task notification
> 
> Thanks,
> 	Frederic
> ---
> 
> Frederic Weisbecker (6):
>       irq_work: Split raised and lazy lists
>       irq_work: Implement remote queueing
>       nohz: Support nohz full remote kick
>       nohz: Switch to nohz full remote kick on timer enqueue
>       nohz: Use nohz own full kick on 2nd task enqueue
>       nohz: Use IPI implicit full barrier against rq->nr_running r/w
> 
> 
>  include/linux/irq_work.h |  5 ++++
>  include/linux/tick.h     |  9 +++++-
>  kernel/irq_work.c        | 76 ++++++++++++++++++++++++++++++------------------
>  kernel/sched/core.c      | 22 ++++++++------
>  kernel/sched/sched.h     | 12 ++++++--
>  kernel/smp.c             |  9 ++++++
>  kernel/time/tick-sched.c | 10 ++++---
>  7 files changed, 97 insertions(+), 46 deletions(-)

Pulled, thanks a lot Frederic!

	Ingo

Re: [GIT PULL] nohz: Move nohz kick out of scheduler IPI, v9

[Peter Zijlstra]

On Wed, Jun 18, 2014 at 06:48:41PM +0200, Ingo Molnar wrote:
> 
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > Please pull the timers/nohz-irq-work-v7 branch that can be found at:
> > 
> 
> Pulled, thanks a lot Frederic!

Ingo, the previous version had one of your machines fall over, is that
machine good now?

Re: [GIT PULL] nohz: Move nohz kick out of scheduler IPI, v9

[Ingo Molnar]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Wed, Jun 18, 2014 at 06:48:41PM +0200, Ingo Molnar wrote:
> > 
> > * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > > Please pull the timers/nohz-irq-work-v7 branch that can be found at:
> > > 
> > 
> > Pulled, thanks a lot Frederic!
> 
> Ingo, the previous version had one of your machines fall over, is that
> machine good now?

It appears so. Will let you know if it still goes bad.

Thanks,

	Ingo