Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-24 Thread Byungchul Park
On Tue, Jul 23, 2019 at 06:47:17AM -0700, Paul E. McKenney wrote: > On Tue, Jul 23, 2019 at 08:05:21PM +0900, Byungchul Park wrote: > > On Fri, Jul 19, 2019 at 04:33:56PM -0400, Joel Fernandes wrote: > > > On Fri, Jul 19, 2019 at 3:57 PM Paul E. McKenney > > > wrote: > > > > > > > > On Fri, Jul

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-24 Thread Byungchul Park
On Tue, Jul 23, 2019 at 09:54:03AM -0700, Paul E. McKenney wrote: > On Tue, Jul 23, 2019 at 06:47:17AM -0700, Paul E. McKenney wrote: > > On Tue, Jul 23, 2019 at 08:05:21PM +0900, Byungchul Park wrote: > > > On Fri, Jul 19, 2019 at 04:33:56PM -0400, Joel Fernandes wrote: > > > > On Fri, Jul 19,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-23 Thread Paul E. McKenney
On Tue, Jul 23, 2019 at 06:47:17AM -0700, Paul E. McKenney wrote: > On Tue, Jul 23, 2019 at 08:05:21PM +0900, Byungchul Park wrote: > > On Fri, Jul 19, 2019 at 04:33:56PM -0400, Joel Fernandes wrote: > > > On Fri, Jul 19, 2019 at 3:57 PM Paul E. McKenney > > > wrote: > > > > > > > > On Fri, Jul

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-23 Thread Paul E. McKenney
On Tue, Jul 23, 2019 at 08:05:21PM +0900, Byungchul Park wrote: > On Fri, Jul 19, 2019 at 04:33:56PM -0400, Joel Fernandes wrote: > > On Fri, Jul 19, 2019 at 3:57 PM Paul E. McKenney > > wrote: > > > > > > On Fri, Jul 19, 2019 at 06:57:58PM +0900, Byungchul Park wrote: > > > > On Fri, Jul 19,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-23 Thread Byungchul Park
On Fri, Jul 19, 2019 at 04:33:56PM -0400, Joel Fernandes wrote: > On Fri, Jul 19, 2019 at 3:57 PM Paul E. McKenney > wrote: > > > > On Fri, Jul 19, 2019 at 06:57:58PM +0900, Byungchul Park wrote: > > > On Fri, Jul 19, 2019 at 4:43 PM Paul E. McKenney > > > wrote: > > > > > > > > On Thu, Jul

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-19 Thread Joel Fernandes
On Fri, Jul 19, 2019 at 3:57 PM Paul E. McKenney wrote: > > On Fri, Jul 19, 2019 at 06:57:58PM +0900, Byungchul Park wrote: > > On Fri, Jul 19, 2019 at 4:43 PM Paul E. McKenney > > wrote: > > > > > > On Thu, Jul 18, 2019 at 08:52:52PM -0400, Joel Fernandes wrote: > > > > On Thu, Jul 18, 2019 at

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-19 Thread Paul E. McKenney
On Fri, Jul 19, 2019 at 06:57:58PM +0900, Byungchul Park wrote: > On Fri, Jul 19, 2019 at 4:43 PM Paul E. McKenney > wrote: > > > > On Thu, Jul 18, 2019 at 08:52:52PM -0400, Joel Fernandes wrote: > > > On Thu, Jul 18, 2019 at 8:40 PM Byungchul Park > > > wrote: > > > [snip] > > > > > - There

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-19 Thread Byungchul Park
On Fri, Jul 19, 2019 at 4:43 PM Paul E. McKenney wrote: > > On Thu, Jul 18, 2019 at 08:52:52PM -0400, Joel Fernandes wrote: > > On Thu, Jul 18, 2019 at 8:40 PM Byungchul Park > > wrote: > > [snip] > > > > - There is a bug in the CPU stopper machinery itself preventing it > > > > from scheduling

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-19 Thread Paul E. McKenney
On Thu, Jul 18, 2019 at 08:52:52PM -0400, Joel Fernandes wrote: > On Thu, Jul 18, 2019 at 8:40 PM Byungchul Park wrote: > [snip] > > > - There is a bug in the CPU stopper machinery itself preventing it > > > from scheduling the stopper on Y. Even though Y is not holding up the > > > grace period.

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Byungchul Park
On Thu, Jul 18, 2019 at 08:52:52PM -0400, Joel Fernandes wrote: > On Thu, Jul 18, 2019 at 8:40 PM Byungchul Park wrote: > [snip] > > > - There is a bug in the CPU stopper machinery itself preventing it > > > from scheduling the stopper on Y. Even though Y is not holding up the > > > grace period.

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Byungchul Park
On Thu, Jul 18, 2019 at 02:34:19PM -0700, Paul E. McKenney wrote: > On Thu, Jul 18, 2019 at 12:14:22PM -0400, Joel Fernandes wrote: > > Trimming the list a bit to keep my noise level low, > > > > On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney > > wrote: > > [snip] > > > > It still feels like

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Joel Fernandes
On Thu, Jul 18, 2019 at 8:40 PM Byungchul Park wrote: [snip] > > - There is a bug in the CPU stopper machinery itself preventing it > > from scheduling the stopper on Y. Even though Y is not holding up the > > grace period. > > Or any thread on Y is busy with preemption/irq disabled preventing

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Joel Fernandes
On Thu, Jul 18, 2019 at 02:34:19PM -0700, Paul E. McKenney wrote: > On Thu, Jul 18, 2019 at 12:14:22PM -0400, Joel Fernandes wrote: > > Trimming the list a bit to keep my noise level low, > > > > On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney > > wrote: > > [snip] > > > > It still feels like

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Byungchul Park
On Thu, Jul 18, 2019 at 12:14:22PM -0400, Joel Fernandes wrote: > Trimming the list a bit to keep my noise level low, > > On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney > wrote: > [snip] > > > It still feels like you guys are hyperfocusing on this one particular > > > > knob. I instead need

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Paul E. McKenney
On Thu, Jul 18, 2019 at 12:14:22PM -0400, Joel Fernandes wrote: > Trimming the list a bit to keep my noise level low, > > On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney > wrote: > [snip] > > > It still feels like you guys are hyperfocusing on this one particular > > > > knob. I instead need

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Joel Fernandes
On Thu, Jul 18, 2019 at 12:14 PM Joel Fernandes wrote: > > Trimming the list a bit to keep my noise level low, > > On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney > wrote: > [snip] > > > It still feels like you guys are hyperfocusing on this one particular > > > > knob. I instead need you to

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-18 Thread Joel Fernandes
Trimming the list a bit to keep my noise level low, On Sat, Jul 13, 2019 at 1:41 PM Paul E. McKenney wrote: [snip] > > It still feels like you guys are hyperfocusing on this one particular > > > knob. I instead need you to look at the interrelating knobs as a group. > > > > Thanks for the

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-15 Thread Paul E. McKenney
On Mon, Jul 15, 2019 at 01:39:24PM -0400, Joel Fernandes wrote: > On Sun, Jul 14, 2019 at 06:56:10AM -0700, Paul E. McKenney wrote: > [snip] > > > > > > > > > > > > > > > > > > > > commit ae91aa0adb14dc33114d566feca2f7cb7a96b8b7 > > > > > > > > > > rcu: Remove debugfs tracing > > > > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-15 Thread Joel Fernandes
On Sun, Jul 14, 2019 at 06:56:10AM -0700, Paul E. McKenney wrote: [snip] > > > > > > > > > > > > > > > > > > commit ae91aa0adb14dc33114d566feca2f7cb7a96b8b7 > > > > > > > > > rcu: Remove debugfs tracing > > > > > > > > > > > > > > > > > > removed all debugfs tracing, gp_max also

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-14 Thread Paul E. McKenney
On Sun, Jul 14, 2019 at 10:39:58PM +0900, Byungchul Park wrote: > On Sun, Jul 14, 2019 at 2:41 AM Paul E. McKenney > wrote: > > > > On Sat, Jul 13, 2019 at 11:42:57AM -0400, Joel Fernandes wrote: > > > On Sat, Jul 13, 2019 at 08:13:30AM -0700, Paul E. McKenney wrote: > > > > On Sat, Jul 13, 2019

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-14 Thread Byungchul Park
On Sun, Jul 14, 2019 at 2:41 AM Paul E. McKenney wrote: > > On Sat, Jul 13, 2019 at 11:42:57AM -0400, Joel Fernandes wrote: > > On Sat, Jul 13, 2019 at 08:13:30AM -0700, Paul E. McKenney wrote: > > > On Sat, Jul 13, 2019 at 10:20:02AM -0400, Joel Fernandes wrote: > > > > On Sat, Jul 13, 2019 at

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Paul E. McKenney
On Sat, Jul 13, 2019 at 11:42:57AM -0400, Joel Fernandes wrote: > On Sat, Jul 13, 2019 at 08:13:30AM -0700, Paul E. McKenney wrote: > > On Sat, Jul 13, 2019 at 10:20:02AM -0400, Joel Fernandes wrote: > > > On Sat, Jul 13, 2019 at 4:47 AM Byungchul Park > > > wrote: > > > > > > > > On Fri, Jul 12,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Joel Fernandes
On Sat, Jul 13, 2019 at 08:13:30AM -0700, Paul E. McKenney wrote: > On Sat, Jul 13, 2019 at 10:20:02AM -0400, Joel Fernandes wrote: > > On Sat, Jul 13, 2019 at 4:47 AM Byungchul Park > > wrote: > > > > > > On Fri, Jul 12, 2019 at 9:51 PM Joel Fernandes > > > wrote: > > > > > > > > On Fri, Jul

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Paul E. McKenney
On Sat, Jul 13, 2019 at 10:20:02AM -0400, Joel Fernandes wrote: > On Sat, Jul 13, 2019 at 4:47 AM Byungchul Park > wrote: > > > > On Fri, Jul 12, 2019 at 9:51 PM Joel Fernandes > > wrote: > > > > > > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > > > On Thu, Jul 11, 2019 at

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Joel Fernandes
On Sat, Jul 13, 2019 at 4:47 AM Byungchul Park wrote: > > On Fri, Jul 12, 2019 at 9:51 PM Joel Fernandes wrote: > > > > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > > > Hmm, speaking of grace period

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Byungchul Park
On Fri, Jul 12, 2019 at 2:50 PM Byungchul Park wrote: > > On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > > > > If there is a real need, something needs to be provided to meet that > > > > need. But in the absence of a real need, past experience has shown > > > > that

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-13 Thread Byungchul Park
On Fri, Jul 12, 2019 at 9:51 PM Joel Fernandes wrote: > > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > > Hmm, speaking of grace period durations, it seems to me the maximum grace > > > period ever is

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Paul E. McKenney
On Fri, Jul 12, 2019 at 09:43:11AM -0400, Joel Fernandes wrote: > On Fri, Jul 12, 2019 at 06:02:42AM -0700, Paul E. McKenney wrote: > > On Fri, Jul 12, 2019 at 08:51:16AM -0400, Joel Fernandes wrote: > > > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > > > On Thu, Jul 11, 2019

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Joel Fernandes
On Fri, Jul 12, 2019 at 06:02:42AM -0700, Paul E. McKenney wrote: > On Fri, Jul 12, 2019 at 08:51:16AM -0400, Joel Fernandes wrote: > > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > > > Hmm, speaking of

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Joel Fernandes
On Fri, Jul 12, 2019 at 06:01:05AM -0700, Paul E. McKenney wrote: > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > On Thu, Jul 11, 2019 at 12:48:18PM -0400, Joel Fernandes wrote: > > > On Thu, Jul 11, 2019 at 08:02:15AM -0700, Paul E. McKenney wrote: > > > > On Thu, Jul 11,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Paul E. McKenney
On Fri, Jul 12, 2019 at 08:51:16AM -0400, Joel Fernandes wrote: > On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > > Hmm, speaking of grace period durations, it seems to me the maximum grace > > > period ever is

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Paul E. McKenney
On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > On Thu, Jul 11, 2019 at 12:48:18PM -0400, Joel Fernandes wrote: > > On Thu, Jul 11, 2019 at 08:02:15AM -0700, Paul E. McKenney wrote: > > > On Thu, Jul 11, 2019 at 09:08:49AM -0400, Joel Fernandes wrote: > > > > On Thu, Jul 11, 2019

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Joel Fernandes
On Fri, Jul 12, 2019 at 03:32:40PM +0900, Byungchul Park wrote: > On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > > Hmm, speaking of grace period durations, it seems to me the maximum grace > > period ever is recorded in rcu_state.gp_max. However it is not read from > > anywhere.

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Byungchul Park
On Thu, Jul 11, 2019 at 03:58:39PM -0400, Joel Fernandes wrote: > Hmm, speaking of grace period durations, it seems to me the maximum grace > period ever is recorded in rcu_state.gp_max. However it is not read from > anywhere. > > Any idea why it was added but not used? > > I am interested in

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-12 Thread Byungchul Park
On Thu, Jul 11, 2019 at 08:02:15AM -0700, Paul E. McKenney wrote: > These would be the tunables controlling how quickly RCU takes its > various actions to encourage the current grace period to end quickly. Seriously one of the most interesting thing over all kernel works. > I would be happy to

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Byungchul Park
On Thu, Jul 11, 2019 at 09:08:49AM -0400, Joel Fernandes wrote: > > Finally, I urge you to join with Joel Fernandes and go through these > > grace-period-duration tuning parameters. Once you guys get your heads > > completely around all of them and how they interact across the different > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Byungchul Park
On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > > > If there is a real need, something needs to be provided to meet that > > > need. But in the absence of a real need, past experience has shown > > > that speculative tuning knobs usually do more harm than good. ;-) > > > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Joel Fernandes
On Thu, Jul 11, 2019 at 12:48:18PM -0400, Joel Fernandes wrote: > On Thu, Jul 11, 2019 at 08:02:15AM -0700, Paul E. McKenney wrote: > > On Thu, Jul 11, 2019 at 09:08:49AM -0400, Joel Fernandes wrote: > > > On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > > > > On Wed, Jul 10,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Joel Fernandes
On Thu, Jul 11, 2019 at 08:02:15AM -0700, Paul E. McKenney wrote: > On Thu, Jul 11, 2019 at 09:08:49AM -0400, Joel Fernandes wrote: > > On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > > > On Wed, Jul 10, 2019 at 10:20:25AM +0900, Byungchul Park wrote: > > > > On Tue, Jul 09,

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Paul E. McKenney
On Thu, Jul 11, 2019 at 09:08:49AM -0400, Joel Fernandes wrote: > On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > > On Wed, Jul 10, 2019 at 10:20:25AM +0900, Byungchul Park wrote: > > > On Tue, Jul 09, 2019 at 05:41:02AM -0700, Paul E. McKenney wrote: > > > > > Hi Paul, > > > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Joel Fernandes
On Thu, Jul 11, 2019 at 05:30:52AM -0700, Paul E. McKenney wrote: > On Wed, Jul 10, 2019 at 10:20:25AM +0900, Byungchul Park wrote: > > On Tue, Jul 09, 2019 at 05:41:02AM -0700, Paul E. McKenney wrote: > > > > Hi Paul, > > > > > > > > IMHO, as much as we want to tune the time for fqs to be

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-11 Thread Paul E. McKenney
On Wed, Jul 10, 2019 at 10:20:25AM +0900, Byungchul Park wrote: > On Tue, Jul 09, 2019 at 05:41:02AM -0700, Paul E. McKenney wrote: > > > Hi Paul, > > > > > > IMHO, as much as we want to tune the time for fqs to be initiated, we > > > can also want to tune the time for the help from scheduler to

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-09 Thread Byungchul Park
On Tue, Jul 09, 2019 at 05:41:02AM -0700, Paul E. McKenney wrote: > > Hi Paul, > > > > IMHO, as much as we want to tune the time for fqs to be initiated, we > > can also want to tune the time for the help from scheduler to start. > > I thought only difference between them is a level of urgency. I

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-09 Thread Paul E. McKenney
On Tue, Jul 09, 2019 at 03:05:58PM +0900, Byungchul Park wrote: > On Mon, Jul 08, 2019 at 06:19:42AM -0700, Paul E. McKenney wrote: > > On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > > > Good morning! > > > > > > On Mon, Jul 08, 2019 at 05:50:13AM -0700, Paul E. McKenney wrote:

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-09 Thread Paul E. McKenney
On Tue, Jul 09, 2019 at 02:58:16PM +0900, Byungchul Park wrote: > On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > > > Actually, the intent was to only allow this to be changed at boot time. > > > Of course, if there is now a good reason to adjust it, it needs > > > to be

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-09 Thread Byungchul Park
On Tue, Jul 09, 2019 at 02:58:16PM +0900, Byungchul Park wrote: > On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > > > Actually, the intent was to only allow this to be changed at boot time. > > > Of course, if there is now a good reason to adjust it, it needs > > > to be

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-09 Thread Byungchul Park
On Mon, Jul 08, 2019 at 06:19:42AM -0700, Paul E. McKenney wrote: > On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > > Good morning! > > > > On Mon, Jul 08, 2019 at 05:50:13AM -0700, Paul E. McKenney wrote: > > > On Mon, Jul 08, 2019 at 03:00:09PM +0900, Byungchul Park wrote: > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-08 Thread Byungchul Park
On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > > Actually, the intent was to only allow this to be changed at boot time. > > Of course, if there is now a good reason to adjust it, it needs > > to be adjustable. So what situation is making you want to change > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-08 Thread Joel Fernandes
On Mon, Jul 08, 2019 at 06:19:42AM -0700, Paul E. McKenney wrote: [snip] > > > Actually, the intent was to only allow this to be changed at boot time. > > > Of course, if there is now a good reason to adjust it, it needs > > > to be adjustable. So what situation is making you want to change > > >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-08 Thread Paul E. McKenney
On Mon, Jul 08, 2019 at 09:03:59AM -0400, Joel Fernandes wrote: > Good morning! > > On Mon, Jul 08, 2019 at 05:50:13AM -0700, Paul E. McKenney wrote: > > On Mon, Jul 08, 2019 at 03:00:09PM +0900, Byungchul Park wrote: > > > jiffies_till_sched_qs is useless if it's readonly as it is used to set >

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-08 Thread Joel Fernandes
Good morning! On Mon, Jul 08, 2019 at 05:50:13AM -0700, Paul E. McKenney wrote: > On Mon, Jul 08, 2019 at 03:00:09PM +0900, Byungchul Park wrote: > > jiffies_till_sched_qs is useless if it's readonly as it is used to set > > jiffies_to_sched_qs with its value regardless of first/next fqs jiffies.

Re: [PATCH] rcu: Make jiffies_till_sched_qs writable

2019-07-08 Thread Paul E. McKenney
On Mon, Jul 08, 2019 at 03:00:09PM +0900, Byungchul Park wrote: > jiffies_till_sched_qs is useless if it's readonly as it is used to set > jiffies_to_sched_qs with its value regardless of first/next fqs jiffies. > And it should be applied immediately on change through sysfs. Actually, the intent