Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-29 Thread Frederic Weisbecker
On Wed, Dec 27, 2017 at 09:58:08PM +0100, Thomas Gleixner wrote: > On Wed, 27 Dec 2017, Thomas Gleixner wrote: > > Bah, no. We need to move that into the nohz logic somehow to prevent that > > repetitive expiry yesterday reprogramming. Lemme think about it some more. > > The patch below should be

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-29 Thread Frederic Weisbecker
On Wed, Dec 27, 2017 at 09:58:08PM +0100, Thomas Gleixner wrote: > On Wed, 27 Dec 2017, Thomas Gleixner wrote: > > Bah, no. We need to move that into the nohz logic somehow to prevent that > > repetitive expiry yesterday reprogramming. Lemme think about it some more. > > The patch below should be

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Wed, 27 Dec 2017, Thomas Gleixner wrote: > Bah, no. We need to move that into the nohz logic somehow to prevent that > repetitive expiry yesterday reprogramming. Lemme think about it some more. The patch below should be the proper cure. Thanks, tglx 8<--- Subject:

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Wed, 27 Dec 2017, Thomas Gleixner wrote: > Bah, no. We need to move that into the nohz logic somehow to prevent that > repetitive expiry yesterday reprogramming. Lemme think about it some more. The patch below should be the proper cure. Thanks, tglx 8<--- Subject:

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Wed, 27 Dec 2017, Thomas Gleixner wrote: > On Tue, 26 Dec 2017, Frederic Weisbecker wrote: > > > On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > > > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > > > > > if ((idle_cpu(cpu) && !need_resched()) ||

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Wed, 27 Dec 2017, Thomas Gleixner wrote: > On Tue, 26 Dec 2017, Frederic Weisbecker wrote: > > > On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > > > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > > > > > if ((idle_cpu(cpu) && !need_resched()) ||

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Tue, 26 Dec 2017, Frederic Weisbecker wrote: > On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > > > if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) > > > > This is too permissive in

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-27 Thread Thomas Gleixner
On Tue, 26 Dec 2017, Frederic Weisbecker wrote: > On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > > > if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) > > > > This is too permissive in

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-26 Thread Frederic Weisbecker
On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) > > This is too permissive in various aspects: > > 1) If need_resched() is set, then the

Re: [patch 2/4] nohz: Prevent erroneous tick stop invocations

2017-12-26 Thread Frederic Weisbecker
On Fri, Dec 22, 2017 at 03:51:13PM +0100, Thomas Gleixner wrote: > The conditions in irq_exit() to invoke tick_nohz_irq_exit() are: > > if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu)) > > This is too permissive in various aspects: > > 1) If need_resched() is set, then the