Re: task isolation discussion at Linux Plumbers

On Sat, Nov 05, 2016 at 12:04:45AM -0400, Chris Metcalf wrote: > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) Which reminds me... One

Re: task isolation discussion at Linux Plumbers

On Sat, Nov 05, 2016 at 12:04:45AM -0400, Chris Metcalf wrote: > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) Which reminds me... One

Re: task isolation discussion at Linux Plumbers

On Mon, 7 Nov 2016 17:55:47 +0100 (CET) Thomas Gleixner wrote: > On Sat, 5 Nov 2016, Chris Metcalf wrote: > > == Remote statistics == > > > > We discussed the possibility of remote statistics gathering, i.e. load > > average etc. The idea would be that we could have

Re: task isolation discussion at Linux Plumbers

On Mon, 7 Nov 2016 17:55:47 +0100 (CET) Thomas Gleixner wrote: > On Sat, 5 Nov 2016, Chris Metcalf wrote: > > == Remote statistics == > > > > We discussed the possibility of remote statistics gathering, i.e. load > > average etc. The idea would be that we could have housekeeping > > core(s)

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 9, 2016 at 8:52 PM, Paul E. McKenney wrote: > On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: >> On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney >> wrote: >> >> Are you planning on changing rcu_nmi_enter()? It

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 9, 2016 at 8:52 PM, Paul E. McKenney wrote: > On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: >> On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney >> wrote: >> >> Are you planning on changing rcu_nmi_enter()? It would make it easier >> to figure out how they interact

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 08:52:13PM -0800, Paul E. McKenney wrote: > On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: > > On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney > > wrote: > > > > Are you planning on changing rcu_nmi_enter()? It would make it

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 08:52:13PM -0800, Paul E. McKenney wrote: > On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: > > On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney > > wrote: > > > > Are you planning on changing rcu_nmi_enter()? It would make it easier > > to figure out

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: > On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney > wrote: > > Are you planning on changing rcu_nmi_enter()? It would make it easier > to figure out how they interact if I could see the code. It

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 05:44:02PM -0800, Andy Lutomirski wrote: > On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney > wrote: > > Are you planning on changing rcu_nmi_enter()? It would make it easier > to figure out how they interact if I could see the code. It already calls

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney wrote: Are you planning on changing rcu_nmi_enter()? It would make it easier to figure out how they interact if I could see the code. > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 9, 2016 at 9:38 AM, Paul E. McKenney wrote: Are you planning on changing rcu_nmi_enter()? It would make it easier to figure out how they interact if I could see the code. > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index dbf20b058f48..342c8ee402d6 100644 > ---

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 06:57:43PM +, Will Deacon wrote: > Hi Paul, > > Just a couple of comments, but they be more suited to Andy. > > On Wed, Nov 09, 2016 at 09:38:08AM -0800, Paul E. McKenney wrote: > > @@ -355,10 +373,33 @@ static bool rcu_dynticks_in_eqs_since(struct > > rcu_dynticks

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 06:57:43PM +, Will Deacon wrote: > Hi Paul, > > Just a couple of comments, but they be more suited to Andy. > > On Wed, Nov 09, 2016 at 09:38:08AM -0800, Paul E. McKenney wrote: > > @@ -355,10 +373,33 @@ static bool rcu_dynticks_in_eqs_since(struct > > rcu_dynticks

Re: task isolation discussion at Linux Plumbers

Hi Paul, Just a couple of comments, but they be more suited to Andy. On Wed, Nov 09, 2016 at 09:38:08AM -0800, Paul E. McKenney wrote: > @@ -355,10 +373,33 @@ static bool rcu_dynticks_in_eqs_since(struct > rcu_dynticks *rdtp, int snap) > static void rcu_dynticks_momentary_idle(void) > { >

Re: task isolation discussion at Linux Plumbers

Hi Paul, Just a couple of comments, but they be more suited to Andy. On Wed, Nov 09, 2016 at 09:38:08AM -0800, Paul E. McKenney wrote: > @@ -355,10 +373,33 @@ static bool rcu_dynticks_in_eqs_since(struct > rcu_dynticks *rdtp, int snap) > static void rcu_dynticks_momentary_idle(void) > { >

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 03:14:35AM -0800, Andy Lutomirski wrote: > On Tue, Nov 8, 2016 at 5:40 PM, Paul E. McKenney > wrote: Thank you for the review and comments! > > commit 49961e272333ac720ac4ccbaba45521bfea259ae > > Author: Paul E. McKenney

Re: task isolation discussion at Linux Plumbers

On Wed, Nov 09, 2016 at 03:14:35AM -0800, Andy Lutomirski wrote: > On Tue, Nov 8, 2016 at 5:40 PM, Paul E. McKenney > wrote: Thank you for the review and comments! > > commit 49961e272333ac720ac4ccbaba45521bfea259ae > > Author: Paul E. McKenney > > Date: Tue Nov 8 14:25:21 2016 -0800 > > > >

Re: task isolation discussion at Linux Plumbers

On Tue, Nov 8, 2016 at 5:40 PM, Paul E. McKenney wrote: > commit 49961e272333ac720ac4ccbaba45521bfea259ae > Author: Paul E. McKenney > Date: Tue Nov 8 14:25:21 2016 -0800 > > rcu: Maintain special bits at bottom of ->dynticks counter

Re: task isolation discussion at Linux Plumbers

On Tue, Nov 8, 2016 at 5:40 PM, Paul E. McKenney wrote: > commit 49961e272333ac720ac4ccbaba45521bfea259ae > Author: Paul E. McKenney > Date: Tue Nov 8 14:25:21 2016 -0800 > > rcu: Maintain special bits at bottom of ->dynticks counter > > Currently, IPIs are used to force other CPUs to

Re: task isolation discussion at Linux Plumbers

2016-11-05 4:04 GMT+00:00 Chris Metcalf : > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) > > Here are the notes I

Re: task isolation discussion at Linux Plumbers

2016-11-05 4:04 GMT+00:00 Chris Metcalf : > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) > > Here are the notes I took; I welcome any

Re: task isolation discussion at Linux Plumbers

On Sat, Nov 05, 2016 at 12:04:45AM -0400, Chris Metcalf wrote: > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) > > Here are the notes I

Re: task isolation discussion at Linux Plumbers

On Sat, Nov 05, 2016 at 12:04:45AM -0400, Chris Metcalf wrote: > A bunch of people got together this week at the Linux Plumbers > Conference to discuss nohz_full, task isolation, and related stuff. > (Thanks to Thomas for getting everyone gathered at one place and time!) > > Here are the notes I

Re: task isolation discussion at Linux Plumbers

On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > == Missing oneshot_stopped callbacks == > > > > > > I raised the issue that various clock_event_device sources don't > > > always support oneshot_stopped, which can cause an

Re: task isolation discussion at Linux Plumbers

On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > == Missing oneshot_stopped callbacks == > > > > > > I raised the issue that various clock_event_device sources don't > > > always support oneshot_stopped, which can cause an

Re: task isolation discussion at Linux Plumbers

On Mon, Nov 07, 2016 at 02:12:13PM -0500, Rik van Riel wrote: > On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > > > > == Missing oneshot_stopped callbacks == > > > > > > > > I raised the issue that various

Re: task isolation discussion at Linux Plumbers

On Mon, Nov 07, 2016 at 02:12:13PM -0500, Rik van Riel wrote: > On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > > > > == Missing oneshot_stopped callbacks == > > > > > > > > I raised the issue that various

Re: task isolation discussion at Linux Plumbers

On Mon, 2016-11-07 at 19:16 +, Will Deacon wrote: > On Mon, Nov 07, 2016 at 02:12:13PM -0500, Rik van Riel wrote: > > > > On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > > > > > > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > > > > > > > > > > > > > > > > ==

Re: task isolation discussion at Linux Plumbers

On Mon, 2016-11-07 at 19:16 +, Will Deacon wrote: > On Mon, Nov 07, 2016 at 02:12:13PM -0500, Rik van Riel wrote: > > > > On Mon, 2016-11-07 at 19:36 +0100, Thomas Gleixner wrote: > > > > > > On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > > > > > > > > > > > > > > > > > > > > > > ==

Re: task isolation discussion at Linux Plumbers

On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > == Missing oneshot_stopped callbacks == > > > > I raised the issue that various clock_event_device sources don't > > always support oneshot_stopped, which can cause an additional > > final interrupt to occur after the timer infrastructure believes

Re: task isolation discussion at Linux Plumbers

On Mon, 7 Nov 2016, Thomas Gleixner wrote: > > == Missing oneshot_stopped callbacks == > > > > I raised the issue that various clock_event_device sources don't > > always support oneshot_stopped, which can cause an additional > > final interrupt to occur after the timer infrastructure believes

Re: task isolation discussion at Linux Plumbers

On Sat, 5 Nov 2016, Chris Metcalf wrote: > == Remote statistics == > > We discussed the possibility of remote statistics gathering, i.e. load > average etc. The idea would be that we could have housekeeping > core(s) periodically iterate over the nohz cores to load their rq > remotely and do

Re: task isolation discussion at Linux Plumbers

On Sat, 5 Nov 2016, Chris Metcalf wrote: > == Remote statistics == > > We discussed the possibility of remote statistics gathering, i.e. load > average etc. The idea would be that we could have housekeeping > core(s) periodically iterate over the nohz cores to load their rq > remotely and do

Re: task isolation discussion at Linux Plumbers

On Sat, 5 Nov 2016, Chris Metcalf wrote: > Here are the notes I took; I welcome any corrections and follow-up. Thank you for writing this up. I hope we can now move forward further on these issues. > == Remote statistics == > > We discussed the possibility of remote statistics gathering, i.e.

Re: task isolation discussion at Linux Plumbers

On Sat, 5 Nov 2016, Chris Metcalf wrote: > Here are the notes I took; I welcome any corrections and follow-up. Thank you for writing this up. I hope we can now move forward further on these issues. > == Remote statistics == > > We discussed the possibility of remote statistics gathering, i.e.

task isolation discussion at Linux Plumbers

A bunch of people got together this week at the Linux Plumbers Conference to discuss nohz_full, task isolation, and related stuff. (Thanks to Thomas for getting everyone gathered at one place and time!) Here are the notes I took; I welcome any corrections and follow-up. == rcu_nocbs == We

task isolation discussion at Linux Plumbers

A bunch of people got together this week at the Linux Plumbers Conference to discuss nohz_full, task isolation, and related stuff. (Thanks to Thomas for getting everyone gathered at one place and time!) Here are the notes I took; I welcome any corrections and follow-up. == rcu_nocbs == We