Re: [PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-03-01 Thread Paul E. McKenney
On Fri, Mar 01, 2024 at 03:30:01PM -0500, Steven Rostedt wrote: > On Fri, 1 Mar 2024 12:25:10 -0800 > "Paul E. McKenney" wrote: > > > > That would work for me. If there are no objections, I will make this > > > change. > > > > But I did check the latency of synchronize_rcu_tasks_rude()

Re: [PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-03-01 Thread Steven Rostedt
On Fri, 1 Mar 2024 12:25:10 -0800 "Paul E. McKenney" wrote: > > That would work for me. If there are no objections, I will make this > > change. > > But I did check the latency of synchronize_rcu_tasks_rude() (about 100ms) > and synchronize_rcu() (about 20ms). This is on a

Re: [PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-03-01 Thread Paul E. McKenney
On Wed, Feb 28, 2024 at 01:16:04PM -0800, Paul E. McKenney wrote: > On Wed, Feb 28, 2024 at 03:22:36PM -0500, Steven Rostedt wrote: > > On Wed, 28 Feb 2024 11:38:29 -0800 > > "Paul E. McKenney" wrote: > > > > > The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that > > > even

Re: [PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-02-28 Thread Paul E. McKenney
On Wed, Feb 28, 2024 at 03:22:36PM -0500, Steven Rostedt wrote: > On Wed, 28 Feb 2024 11:38:29 -0800 > "Paul E. McKenney" wrote: > > > The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that > > even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY > > might see

Re: [PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-02-28 Thread Steven Rostedt
On Wed, 28 Feb 2024 11:38:29 -0800 "Paul E. McKenney" wrote: > The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that > even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY > might see the occasional preemption, and that this preemption just might > happen

[PATCH RFC ftrace] Chose RCU Tasks based on TASKS_RCU rather than PREEMPTION

2024-02-28 Thread Paul E. McKenney
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY might see the occasional preemption, and that this preemption just might happen within a trampoline. Therefore, update ftrace_shutdown() to invoke