Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 12, 2017 at 10:26:12AM -0700, John Stultz wrote: > On Fri, May 12, 2017 at 8:14 AM, Miroslav Lichvar wrote: > > I see this with real PHCs and PTP/NTP synchronization too. It's very > > confusing when the timekeeping changes so much for no apparent reason. > > If

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 12, 2017 at 10:26:12AM -0700, John Stultz wrote: > On Fri, May 12, 2017 at 8:14 AM, Miroslav Lichvar wrote: > > I see this with real PHCs and PTP/NTP synchronization too. It's very > > confusing when the timekeeping changes so much for no apparent reason. > > If we can't remove the

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 12, 2017 at 8:14 AM, Miroslav Lichvar wrote: > On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: >> On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: >> > I spent some time trying to figure out a workaround for the nanosecond >> > rounding, but I didn't

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 12, 2017 at 8:14 AM, Miroslav Lichvar wrote: > On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: >> On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: >> > I spent some time trying to figure out a workaround for the nanosecond >> > rounding, but I didn't find anything that

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: > On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: > > I spent some time trying to figure out a workaround for the nanosecond > > rounding, but I didn't find anything that wouldn't complicate the mult > > adjustment logic and bring back

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: > On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: > > I spent some time trying to figure out a workaround for the nanosecond > > rounding, but I didn't find anything that wouldn't complicate the mult > > adjustment logic and bring back

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: > On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: > > It seems it may be a while before the old vsyscalls are fixed. How > > about including only the first two patches from this set for now? > > Hey! Sorry for the slow response here, I

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, 15 Jul 2014, John Stultz wrote: > On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: > > On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: > >> Another area we have to be careful with is there are still > >> architectures (powerpc and ia64) which haven't switched from the old > >>

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, 15 Jul 2014, John Stultz wrote: On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: Another area we have to be careful with is there are still architectures (powerpc and ia64) which haven't switched from the old vsyscall

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Tue, Jul 15, 2014 at 09:02:38PM -0700, John Stultz wrote: On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: It seems it may be a while before the old vsyscalls are fixed. How about including only the first two patches from this set for now? Hey! Sorry for the slow response here, I was on

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: > On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: >> Another area we have to be careful with is there are still >> architectures (powerpc and ia64) which haven't switched from the old >> vsyscall rounding logic

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On 07/08/2014 04:08 AM, Miroslav Lichvar wrote: On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: Another area we have to be careful with is there are still architectures (powerpc and ia64) which haven't switched from the old vsyscall rounding logic

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: > Another area we have to be careful with is there are still > architectures (powerpc and ia64) which haven't switched from the old > vsyscall rounding logic (CONFIG_GENERIC_TIME_VSYSCALL_OLD). In these > cases we add up to 1ns of error

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: Another area we have to be careful with is there are still architectures (powerpc and ia64) which haven't switched from the old vsyscall rounding logic (CONFIG_GENERIC_TIME_VSYSCALL_OLD). In these cases we add up to 1ns of error each

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: > On Mon, May 19, 2014 at 3:14 AM, Miroslav Lichvar wrote: > > Ok, so it seems to be almost identical to my patch now. The only two > > differences seem to be the removal of the ntp_error correction to > > change the effective clock

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 10:57:29AM -0700, John Stultz wrote: On Mon, May 19, 2014 at 3:14 AM, Miroslav Lichvar mlich...@redhat.com wrote: Ok, so it seems to be almost identical to my patch now. The only two differences seem to be the removal of the ntp_error correction to change the

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 3:14 AM, Miroslav Lichvar wrote: > On Fri, May 16, 2014 at 05:56:41PM -0700, John Stultz wrote: >> This version of the patch set corrects a few issues Miroslav pointed >> out, as well as adapts his approach almost completely for the last >> patch. This pulls the results in

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 16, 2014 at 05:56:41PM -0700, John Stultz wrote: > This version of the patch set corrects a few issues Miroslav pointed > out, as well as adapts his approach almost completely for the last > patch. This pulls the results in to be very close to his original > patch. Ok, so it seems to

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Fri, May 16, 2014 at 05:56:41PM -0700, John Stultz wrote: This version of the patch set corrects a few issues Miroslav pointed out, as well as adapts his approach almost completely for the last patch. This pulls the results in to be very close to his original patch. Ok, so it seems to be

Re: [PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

On Mon, May 19, 2014 at 3:14 AM, Miroslav Lichvar mlich...@redhat.com wrote: On Fri, May 16, 2014 at 05:56:41PM -0700, John Stultz wrote: This version of the patch set corrects a few issues Miroslav pointed out, as well as adapts his approach almost completely for the last patch. This pulls

[PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

I managed to find some time to further work on the next iteration here. This patch set, based on ideas from Miroslav, tries to improve the ntp freq steering when using NOHZ. Rather then just doing error proportional correction, this patchset splits the logic to two steps: frequency correction

[PATCH 0/3] timekeeping: Improved NOHZ frequency steering (v2)

I managed to find some time to further work on the next iteration here. This patch set, based on ideas from Miroslav, tries to improve the ntp freq steering when using NOHZ. Rather then just doing error proportional correction, this patchset splits the logic to two steps: frequency correction