[PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[Jon Hunter]

This patch series ensures that the wrapping of the clocksource will not 
be missed if the kernel sleeps for longer periods and allows 32-bit 
machines to sleep for longer than 2.15 seconds.

Jon Hunter (2):
   Dynamic Tick: Prevent clocksource wrapping during idle
   Dynamic Tick: Allow 32-bit machines to sleep for more than 2.15
     seconds

  include/linux/clockchips.h |    6 ++--
  include/linux/time.h       |    1 +
  kernel/hrtimer.c           |    2 +-
  kernel/time/clockevents.c  |   10 ++++----
  kernel/time/tick-oneshot.c |    2 +-
  kernel/time/tick-sched.c   |   36 +++++++++++++++++++++++----------
  kernel/time/timekeeping.c  |   47 
++++++++++++++++++++++++++++++++++++++++++++
  kernel/time/timer_list.c   |    4 +-
  8 files changed, 85 insertions(+), 23 deletions(-)

[PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[Jon Hunter]

From: Jon Hunter <jon-hunter@ti.com>

This is a resend of the patch series shown here:
http://www.spinics.net/lists/kernel/msg891029.html

This patch series has been rebase on the linux-2.6-tip timers/core branch per
request from Thomas Gleixner.

This patch series ensures that the wrapping of the clocksource will not be
missed if the kernel sleeps for longer periods and allows 32-bit machines to
sleep for longer than 2.15 seconds.

Jon Hunter (2):
  Dynamic Tick: Prevent clocksource wrapping during idle
  Dynamic Tick: Allow 32-bit machines to sleep for more than 2.15
    seconds

 include/linux/clockchips.h  |    6 ++--
 include/linux/clocksource.h |    2 +
 include/linux/time.h        |    1 +
 kernel/hrtimer.c            |    2 +-
 kernel/time/clockevents.c   |   10 ++++----
 kernel/time/clocksource.c   |   47 +++++++++++++++++++++++++++++++++++
 kernel/time/tick-oneshot.c  |    2 +-
 kernel/time/tick-sched.c    |   57 ++++++++++++++++++++++++++++++++----------
 kernel/time/timekeeping.c   |   11 ++++++++
 kernel/time/timer_list.c    |    4 +-
 10 files changed, 116 insertions(+), 26 deletions(-)

Re: [PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[john stultz]

On Tue, Aug 18, 2009 at 9:45 AM, Jon Hunter <jon-hunter@ti.com> wrote:
> From: Jon Hunter <jon-hunter@ti.com>
>
> This is a resend of the patch series shown here:
> http://www.spinics.net/lists/kernel/msg891029.html
>
> This patch series has been rebase on the linux-2.6-tip timers/core branch per
> request from Thomas Gleixner.
>
> This patch series ensures that the wrapping of the clocksource will not be
> missed if the kernel sleeps for longer periods and allows 32-bit machines to
> sleep for longer than 2.15 seconds.
>
> Jon Hunter (2):
>  Dynamic Tick: Prevent clocksource wrapping during idle
>  Dynamic Tick: Allow 32-bit machines to sleep for more than 2.15
>    seconds

I could have sworn this was in mainline by now, but I recently was
looking for the code and can't find it there or in -tip either.

Thomas, are they just hiding somewhere I can't find?

Jon, you've been terribly patient and great about resubmitting these
patches over and over. If I'm not just being crazy and missing these
patches in front of my nose, are you still willing to submit them
again? I think they'll be quite useful as folks start pushing the NOHZ
idle times out.

thanks
-john

Re: [PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[Jon Hunter]

john stultz wrote:
> I could have sworn this was in mainline by now, but I recently was
> looking for the code and can't find it there or in -tip either.
> 
> Thomas, are they just hiding somewhere I can't find?
> 
> Jon, you've been terribly patient and great about resubmitting these
> patches over and over. If I'm not just being crazy and missing these
> patches in front of my nose, are you still willing to submit them
> again? I think they'll be quite useful as folks start pushing the NOHZ
> idle times out.

Absolutely! It is still on my to-do list, but unfortunately, I got busy 
with a couple other things.

With regard to the last patch set I submitted for this, Thomas had an 
issue with one of the patches. I understand the concern, but I am not 
sure  which would be the preferred way to handle this. See the below thread:

http://marc.info/?l=linux-kernel&m=125062817124381&w=2

If you or Thomas have any feedback on this, I could re-work the patch 
against the latest kernel tree.

Cheers
Jon

Re: [PATCH 0/2] Dynamic Tick: Enabling longer sleep times on 32-bit machines

[john stultz]

On Wed, 2009-11-11 at 14:57 -0600, Jon Hunter wrote:
> john stultz wrote:
> > I could have sworn this was in mainline by now, but I recently was
> > looking for the code and can't find it there or in -tip either.
> > 
> > Thomas, are they just hiding somewhere I can't find?
> > 
> > Jon, you've been terribly patient and great about resubmitting these
> > patches over and over. If I'm not just being crazy and missing these
> > patches in front of my nose, are you still willing to submit them
> > again? I think they'll be quite useful as folks start pushing the NOHZ
> > idle times out.
> 
> Absolutely! It is still on my to-do list, but unfortunately, I got busy 
> with a couple other things.
> 
> With regard to the last patch set I submitted for this, Thomas had an 
> issue with one of the patches. I understand the concern, but I am not 
> sure  which would be the preferred way to handle this. See the below thread:
> 
> http://marc.info/?l=linux-kernel&m=125062817124381&w=2
> 
> If you or Thomas have any feedback on this, I could re-work the patch 
> against the latest kernel tree.

Ok. I think Thomas is right there, setting the expiration to
max_time_delta makes the most sense. Honestly I suspect we don't ever
hit that case in the current code (no timers for 12 days), so its
probably an untested code path as it stands.

thanks
-john