Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-25 Thread Paul E. McKenney
On Mon, Mar 25, 2019 at 08:08:00AM -0700, Paul E. McKenney wrote: > On Mon, Mar 25, 2019 at 09:41:29AM -0400, Joel Fernandes wrote: > > On Sun, Mar 24, 2019 at 04:42:11PM -0700, Paul E. McKenney wrote: > > > On Sat, Mar 23, 2019 at 09:10:02AM -0700, Paul E. McKenney wrote: > > > > On Fri, Mar 22,

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-25 Thread Paul E. McKenney
On Mon, Mar 25, 2019 at 09:41:29AM -0400, Joel Fernandes wrote: > On Sun, Mar 24, 2019 at 04:42:11PM -0700, Paul E. McKenney wrote: > > On Sat, Mar 23, 2019 at 09:10:02AM -0700, Paul E. McKenney wrote: > > > On Fri, Mar 22, 2019 at 05:25:19PM -0700, Paul E. McKenney wrote: > > > > On Fri, Mar 22,

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-25 Thread Joel Fernandes
On Sun, Mar 24, 2019 at 04:42:11PM -0700, Paul E. McKenney wrote: > On Sat, Mar 23, 2019 at 09:10:02AM -0700, Paul E. McKenney wrote: > > On Fri, Mar 22, 2019 at 05:25:19PM -0700, Paul E. McKenney wrote: > > > On Fri, Mar 22, 2019 at 07:48:19PM -0400, Joel Fernandes wrote: > > > > On Wed, Mar 20,

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-24 Thread Paul E. McKenney
On Sat, Mar 23, 2019 at 09:10:02AM -0700, Paul E. McKenney wrote: > On Fri, Mar 22, 2019 at 05:25:19PM -0700, Paul E. McKenney wrote: > > On Fri, Mar 22, 2019 at 07:48:19PM -0400, Joel Fernandes wrote: > > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > > Running

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-24 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 05:25:19PM -0700, Paul E. McKenney wrote: > On Fri, Mar 22, 2019 at 07:48:19PM -0400, Joel Fernandes wrote: > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > Running RCU out of softirq is a problem for some workloads that would > > > like

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Joel Fernandes
On Fri, Mar 22, 2019 at 05:25:19PM -0700, Paul E. McKenney wrote: > On Fri, Mar 22, 2019 at 07:48:19PM -0400, Joel Fernandes wrote: > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > Running RCU out of softirq is a problem for some workloads that would > > > like

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 07:48:19PM -0400, Joel Fernandes wrote: > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > Running RCU out of softirq is a problem for some workloads that would > > like to manage RCU core processing independently of other softirq > > work, for

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Joel Fernandes
On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > Running RCU out of softirq is a problem for some workloads that would > like to manage RCU core processing independently of other softirq > work, for example, setting kthread priority. This commit therefore > introduces

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 09:26:35AM -0700, Paul E. McKenney wrote: > On Fri, Mar 22, 2019 at 11:50:49AM -0400, Joel Fernandes wrote: > > On Fri, Mar 22, 2019 at 07:58:23AM -0700, Paul E. McKenney wrote: > > [snip] > > > > > > #ifdef CONFIG_RCU_NOCB_CPU > > > > > > static cpumask_var_t

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 11:50:49AM -0400, Joel Fernandes wrote: > On Fri, Mar 22, 2019 at 07:58:23AM -0700, Paul E. McKenney wrote: > [snip] > > > > > #ifdef CONFIG_RCU_NOCB_CPU > > > > > static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks > > > > > offloaded. */ > > > > > @@ -94,6

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Joel Fernandes
On Fri, Mar 22, 2019 at 07:58:23AM -0700, Paul E. McKenney wrote: [snip] > > > > #ifdef CONFIG_RCU_NOCB_CPU > > > > static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks > > > > offloaded. */ > > > > @@ -94,6 +72,8 @@ static void __init rcu_bootup_announce_oddness(void) > > > >

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 09:42:07AM -0400, Joel Fernandes wrote: > On Thu, Mar 21, 2019 at 04:32:44PM -0700, Paul E. McKenney wrote: > > On Wed, Mar 20, 2019 at 04:46:01PM -0700, Paul E. McKenney wrote: > > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > > Running

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Fri, Mar 22, 2019 at 12:35:53AM -0700, Paul E. McKenney wrote: > On Thu, Mar 21, 2019 at 04:32:44PM -0700, Paul E. McKenney wrote: > > On Wed, Mar 20, 2019 at 04:46:01PM -0700, Paul E. McKenney wrote: > > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > >

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Paul E. McKenney
On Thu, Mar 21, 2019 at 04:32:44PM -0700, Paul E. McKenney wrote: > On Wed, Mar 20, 2019 at 04:46:01PM -0700, Paul E. McKenney wrote: > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > Running RCU out of softirq is a problem for some workloads that would > > >

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-22 Thread Joel Fernandes
On Thu, Mar 21, 2019 at 04:32:44PM -0700, Paul E. McKenney wrote: > On Wed, Mar 20, 2019 at 04:46:01PM -0700, Paul E. McKenney wrote: > > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > > Running RCU out of softirq is a problem for some workloads that would > > >

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-21 Thread Paul E. McKenney
On Wed, Mar 20, 2019 at 04:46:01PM -0700, Paul E. McKenney wrote: > On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > > Running RCU out of softirq is a problem for some workloads that would > > like to manage RCU core processing independently of other softirq > > work,

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-21 Thread Paul E. McKenney
On Thu, Mar 21, 2019 at 09:27:37AM +0100, Sebastian Andrzej Siewior wrote: > On 2019-03-20 16:46:01 [-0700], Paul E. McKenney wrote: > > Thank you! I reverted v2 and applied this one with the same sort of > > update. Testing is going well thus far aside from my failing to add > > the required

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-21 Thread Sebastian Andrzej Siewior
On 2019-03-20 16:46:01 [-0700], Paul E. McKenney wrote: > Thank you! I reverted v2 and applied this one with the same sort of > update. Testing is going well thus far aside from my failing to add > the required "=0" after the rcutree.use_softirq. I will probably not > be the only one who will

Re: [PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-20 Thread Paul E. McKenney
On Wed, Mar 20, 2019 at 10:13:33PM +0100, Sebastian Andrzej Siewior wrote: > Running RCU out of softirq is a problem for some workloads that would > like to manage RCU core processing independently of other softirq > work, for example, setting kthread priority. This commit therefore > introduces

[PATCH v3] rcu: Allow to eliminate softirq processing from rcutree

2019-03-20 Thread Sebastian Andrzej Siewior
Running RCU out of softirq is a problem for some workloads that would like to manage RCU core processing independently of other softirq work, for example, setting kthread priority. This commit therefore introduces the `rcunosoftirq' option which moves the RCU core work from softirq to a