Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-28 Thread Paul E. McKenney
On Fri, Jun 28, 2019 at 02:37:24PM -0500, Scott Wood wrote: > On Thu, 2019-06-27 at 17:52 -0700, Paul E. McKenney wrote: > > On Thu, Jun 27, 2019 at 05:46:27PM -0500, Scott Wood wrote: > > > On Thu, 2019-06-27 at 13:50 -0700, Paul E. McKenney wrote: > > > > If by IPI-to-self you mean the IRQ work

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-28 Thread Scott Wood
On Thu, 2019-06-27 at 17:52 -0700, Paul E. McKenney wrote: > On Thu, Jun 27, 2019 at 05:46:27PM -0500, Scott Wood wrote: > > On Thu, 2019-06-27 at 13:50 -0700, Paul E. McKenney wrote: > > > If by IPI-to-self you mean the IRQ work trick, that isn't implemented > > > across all architectures yet, is

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-27 Thread Paul E. McKenney
On Thu, Jun 27, 2019 at 05:46:27PM -0500, Scott Wood wrote: > On Thu, 2019-06-27 at 13:50 -0700, Paul E. McKenney wrote: > > On Thu, Jun 27, 2019 at 03:16:09PM -0500, Scott Wood wrote: > > > On Thu, 2019-06-27 at 11:00 -0700, Paul E. McKenney wrote: > > > > On Wed, Jun 26, 2019 at 11:49:16AM

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-27 Thread Scott Wood
On Thu, 2019-06-27 at 13:50 -0700, Paul E. McKenney wrote: > On Thu, Jun 27, 2019 at 03:16:09PM -0500, Scott Wood wrote: > > On Thu, 2019-06-27 at 11:00 -0700, Paul E. McKenney wrote: > > > On Wed, Jun 26, 2019 at 11:49:16AM -0500, Scott Wood wrote: > > > > > > > > > > On Fri, 21 Jun 2019

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-27 Thread Paul E. McKenney
On Thu, Jun 27, 2019 at 03:16:09PM -0500, Scott Wood wrote: > On Thu, 2019-06-27 at 11:00 -0700, Paul E. McKenney wrote: > > On Wed, Jun 26, 2019 at 11:49:16AM -0500, Scott Wood wrote: > > > On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote: > > > > On Fri, 21 Jun 2019 16:59:55 -0700 > > > >

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-27 Thread Scott Wood
On Thu, 2019-06-27 at 11:00 -0700, Paul E. McKenney wrote: > On Wed, Jun 26, 2019 at 11:49:16AM -0500, Scott Wood wrote: > > On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote: > > > On Fri, 21 Jun 2019 16:59:55 -0700 > > > "Paul E. McKenney" wrote: > > > > > > > I have no objection to the

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-27 Thread Paul E. McKenney
On Wed, Jun 26, 2019 at 11:49:16AM -0500, Scott Wood wrote: > On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote: > > On Fri, 21 Jun 2019 16:59:55 -0700 > > "Paul E. McKenney" wrote: > > > > > I have no objection to the outlawing of a number of these sequences in > > > mainline, but am

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-26 Thread Scott Wood
On Wed, 2019-06-26 at 11:08 -0400, Steven Rostedt wrote: > On Fri, 21 Jun 2019 16:59:55 -0700 > "Paul E. McKenney" wrote: > > > I have no objection to the outlawing of a number of these sequences in > > mainline, but am rather pointing out that until they really are outlawed > > and eliminated,

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-26 Thread Steven Rostedt
On Fri, 21 Jun 2019 16:59:55 -0700 "Paul E. McKenney" wrote: > I have no objection to the outlawing of a number of these sequences in > mainline, but am rather pointing out that until they really are outlawed > and eliminated, rcutorture must continue to test them in mainline. > Of course, an

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-21 Thread Paul E. McKenney
On Fri, Jun 21, 2019 at 06:38:21PM +0200, Sebastian Andrzej Siewior wrote: > On 2019-06-20 14:18:26 [-0700], Paul E. McKenney wrote: > > > Example #1: > > > > > > 1. preempt_disable() > > > 2. local_bh_disable() > > > 3. preempt_enable() > > > 4. local_bh_enable() > > > > > > Example #2: > > >

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-21 Thread Sebastian Andrzej Siewior
On 2019-06-20 14:18:26 [-0700], Paul E. McKenney wrote: > > Example #1: > > > > 1. preempt_disable() > > 2. local_bh_disable() > > 3. preempt_enable() > > 4. local_bh_enable() > > > > Example #2: > > > > 1. rcu_read_lock() > > 2. local_irq_disable() > > 3. rcu_read_unlock() > > 4.

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-20 Thread Scott Wood
On Thu, 2019-06-20 at 14:18 -0700, Paul E. McKenney wrote: > On Tue, Jun 18, 2019 at 08:19:08PM -0500, Scott Wood wrote: > > rcutorture was generating some nesting scenarios that are not > > reasonable. Constrain the state selection to avoid them. > > > > Example #1: > > > > 1.

Re: [RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-20 Thread Paul E. McKenney
On Tue, Jun 18, 2019 at 08:19:08PM -0500, Scott Wood wrote: > rcutorture was generating some nesting scenarios that are not > reasonable. Constrain the state selection to avoid them. > > Example #1: > > 1. preempt_disable() > 2. local_bh_disable() > 3. preempt_enable() > 4. local_bh_enable() >

[RFC PATCH RT 4/4] rcutorture: Avoid problematic critical section nesting

2019-06-18 Thread Scott Wood
rcutorture was generating some nesting scenarios that are not reasonable. Constrain the state selection to avoid them. Example #1: 1. preempt_disable() 2. local_bh_disable() 3. preempt_enable() 4. local_bh_enable() On PREEMPT_RT, BH disabling takes a local lock only when called in non-atomic