Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-13 Thread Paul E. McKenney
On Wed, May 13, 2020 at 03:07:26PM +1000, Dave Chinner wrote: > On Tue, May 12, 2020 at 08:18:26PM -0700, Paul E. McKenney wrote: > > On Wed, May 13, 2020 at 11:32:38AM +1000, Dave Chinner wrote: > > > On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: > > > > On Sat, May 09, 2020

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-13 Thread Paul E. McKenney
On Wed, May 13, 2020 at 07:35:25AM +0300, Konstantin Khlebnikov wrote: > On 13/05/2020 06.18, Paul E. McKenney wrote: > > On Wed, May 13, 2020 at 11:32:38AM +1000, Dave Chinner wrote: > > > On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: > > > > On Sat, May 09, 2020 at 11:54:40AM

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-12 Thread Dave Chinner
On Tue, May 12, 2020 at 08:18:26PM -0700, Paul E. McKenney wrote: > On Wed, May 13, 2020 at 11:32:38AM +1000, Dave Chinner wrote: > > On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: > > > On Sat, May 09, 2020 at 11:54:40AM +0300, Konstantin Khlebnikov wrote: > > > > On 08/05/2020

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-12 Thread Konstantin Khlebnikov
On 13/05/2020 06.18, Paul E. McKenney wrote: On Wed, May 13, 2020 at 11:32:38AM +1000, Dave Chinner wrote: On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: On Sat, May 09, 2020 at 11:54:40AM +0300, Konstantin Khlebnikov wrote: On 08/05/2020 17.46, Paul E. McKenney wrote:

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-12 Thread Paul E. McKenney
On Wed, May 13, 2020 at 11:32:38AM +1000, Dave Chinner wrote: > On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: > > On Sat, May 09, 2020 at 11:54:40AM +0300, Konstantin Khlebnikov wrote: > > > On 08/05/2020 17.46, Paul E. McKenney wrote: > > > > Easy for me to provide "start fast

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-12 Thread Dave Chinner
On Sat, May 09, 2020 at 09:09:00AM -0700, Paul E. McKenney wrote: > On Sat, May 09, 2020 at 11:54:40AM +0300, Konstantin Khlebnikov wrote: > > On 08/05/2020 17.46, Paul E. McKenney wrote: > > > Easy for me to provide "start fast and inefficient mode" and "stop fast > > > and inefficient mode" APIs

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-09 Thread Paul E. McKenney
On Sat, May 09, 2020 at 11:54:40AM +0300, Konstantin Khlebnikov wrote: > On 08/05/2020 17.46, Paul E. McKenney wrote: > > On Fri, May 08, 2020 at 12:00:28PM +0300, Konstantin Khlebnikov wrote: > > > On 07/05/2020 22.09, Paul E. McKenney wrote: > > > > On Thu, May 07, 2020 at 02:31:02PM -0400,

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-09 Thread Konstantin Khlebnikov
On 08/05/2020 17.46, Paul E. McKenney wrote: On Fri, May 08, 2020 at 12:00:28PM +0300, Konstantin Khlebnikov wrote: On 07/05/2020 22.09, Paul E. McKenney wrote: On Thu, May 07, 2020 at 02:31:02PM -0400, Johannes Weiner wrote: On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote:

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-08 Thread Paul E. McKenney
On Fri, May 08, 2020 at 09:37:43PM +0800, Hillf Danton wrote: > > On Thu, 7 May 2020 08:49:10 Paul E. McKenney wrote: > > > > > +static void rcu_mph_info(void *data) > > > > This pointer will always be _state, so why not ignore the pointer > > and use "rcu_state" below? > > > Yes you're right.

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-08 Thread Paul E. McKenney
On Fri, May 08, 2020 at 12:00:28PM +0300, Konstantin Khlebnikov wrote: > On 07/05/2020 22.09, Paul E. McKenney wrote: > > On Thu, May 07, 2020 at 02:31:02PM -0400, Johannes Weiner wrote: > > > On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote: > > > > On Thu, May 07, 2020 at

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-08 Thread Konstantin Khlebnikov
On 07/05/2020 22.09, Paul E. McKenney wrote: On Thu, May 07, 2020 at 02:31:02PM -0400, Johannes Weiner wrote: On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote: On Thu, May 07, 2020 at 01:00:06PM -0400, Johannes Weiner wrote: On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Paul E. McKenney
On Thu, May 07, 2020 at 02:31:02PM -0400, Johannes Weiner wrote: > On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote: > > On Thu, May 07, 2020 at 01:00:06PM -0400, Johannes Weiner wrote: > > > On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > > > > On Wed, 6 May 2020

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Johannes Weiner
On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote: > On Thu, May 07, 2020 at 01:00:06PM -0400, Johannes Weiner wrote: > > On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > > > On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" > > > wrote: > > > > > > > This

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Paul E. McKenney
On Thu, May 07, 2020 at 10:09:03AM -0700, Paul E. McKenney wrote: > On Thu, May 07, 2020 at 01:00:06PM -0400, Johannes Weiner wrote: > > On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > > > On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" > > > wrote: > > > > > > > This

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Paul E. McKenney
On Thu, May 07, 2020 at 01:00:06PM -0400, Johannes Weiner wrote: > On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > > On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" > > wrote: > > > > > This commit adds a shrinker so as to inform RCU when memory is scarce. > > > RCU

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Johannes Weiner
On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" > wrote: > > > This commit adds a shrinker so as to inform RCU when memory is scarce. > > RCU responds by shifting into the same fast and inefficient mode that is > > used in

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-07 Thread Paul E. McKenney
On Thu, May 07, 2020 at 05:36:47PM +0800, Hillf Danton wrote: > > Hello Paul > > On Wed, 6 May 2020 17:42:40 Paul E. McKenney wrote: > > > > This commit adds a shrinker so as to inform RCU when memory is scarce. > > A simpler hook is added in the logic of kswapd for subscribing the info > that

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-06 Thread Paul E. McKenney
On Wed, May 06, 2020 at 05:55:35PM -0700, Andrew Morton wrote: > On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" > wrote: > > > This commit adds a shrinker so as to inform RCU when memory is scarce. > > RCU responds by shifting into the same fast and inefficient mode that is > > used in

Re: [PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-06 Thread Andrew Morton
On Wed, 6 May 2020 17:42:40 -0700 "Paul E. McKenney" wrote: > This commit adds a shrinker so as to inform RCU when memory is scarce. > RCU responds by shifting into the same fast and inefficient mode that is > used in the presence of excessive numbers of RCU callbacks. RCU remains > in this

[PATCH RFC tip/core/rcu] Add shrinker to shift to fast/inefficient GP mode

2020-05-06 Thread Paul E. McKenney
This commit adds a shrinker so as to inform RCU when memory is scarce. RCU responds by shifting into the same fast and inefficient mode that is used in the presence of excessive numbers of RCU callbacks. RCU remains in this state for one-tenth of a second, though this time window can be extended