[PATCH] x86/xen/time: set ->min_delta_ticks and ->max_delta_ticks
In preparation for making the clockevents core NTP correction aware, all clockevent device drivers must set ->min_delta_ticks and ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a clockevent device's rate is going to change dynamically and thus, the ratio of ns to ticks ceases to stay invariant. Make the x86 arch's xen clockevent driver initialize these fields properly. This patch alone doesn't introduce any change in functionality as the clockevents core still looks exclusively at the (untouched) ->min_delta_ns and ->max_delta_ns. As soon as this has changed, a followup patch will purge the initialization of ->min_delta_ns and ->max_delta_ns from this driver. Signed-off-by: Nicolai Stange --- Notes: This prerequisite patch is part of a larger effort to feed NTP corrections into the clockevent devices' frequencies and thus avoiding their notion of time to diverge from the system's one. If you're interested, the current state of the whole series can be found at [1]. If you haven't got any objections and these prerequisites get merged by 4.12 everywhere, I'll proceed with the remainder of this series in 4.13. Applicable to next-20170324 as well as to John' Stultz tree [2]. [1] git://nicst.de/linux.git cev-freq-adj.v10.fortglx-4.12-time https://nicst.de/git/?p=linux.git;a=shortlog;h=refs/heads/cev-freq-adj.v10.fortglx-4.12-time [2] https://git.linaro.org/people/john.stultz/linux.git fortglx/4.12/time arch/x86/xen/time.c | 4 1 file changed, 4 insertions(+) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 1e69956d7852..7a3089285c59 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -209,7 +209,9 @@ static const struct clock_event_device xen_timerop_clockevent = { .features = CLOCK_EVT_FEAT_ONESHOT, .max_delta_ns = 0x, + .max_delta_ticks= 0x, .min_delta_ns = TIMER_SLOP, + .min_delta_ticks= TIMER_SLOP, .mult = 1, .shift = 0, @@ -268,7 +270,9 @@ static const struct clock_event_device xen_vcpuop_clockevent = { .features = CLOCK_EVT_FEAT_ONESHOT, .max_delta_ns = 0x, + .max_delta_ticks = 0x, .min_delta_ns = TIMER_SLOP, + .min_delta_ticks = TIMER_SLOP, .mult = 1, .shift = 0, -- 2.12.0
Re: [PATCH] x86/xen/time: set ->min_delta_ticks and ->max_delta_ticks
On 30/03/17 22:06, Nicolai Stange wrote: > In preparation for making the clockevents core NTP correction aware, > all clockevent device drivers must set ->min_delta_ticks and > ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a > clockevent device's rate is going to change dynamically and thus, the > ratio of ns to ticks ceases to stay invariant. > > Make the x86 arch's xen clockevent driver initialize these fields properly. > > This patch alone doesn't introduce any change in functionality as the > clockevents core still looks exclusively at the (untouched) ->min_delta_ns > and ->max_delta_ns. As soon as this has changed, a followup patch will > purge the initialization of ->min_delta_ns and ->max_delta_ns from this > driver. > > Signed-off-by: Nicolai Stange Applied to xen/tip for-linus-4.12 Thanks, Juergen
Re: [PATCH] x86/xen/time: set ->min_delta_ticks and ->max_delta_ticks
On 03/30/2017 04:06 PM, Nicolai Stange wrote: > In preparation for making the clockevents core NTP correction aware, > all clockevent device drivers must set ->min_delta_ticks and > ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a > clockevent device's rate is going to change dynamically and thus, the > ratio of ns to ticks ceases to stay invariant. > > Make the x86 arch's xen clockevent driver initialize these fields properly. > > This patch alone doesn't introduce any change in functionality as the > clockevents core still looks exclusively at the (untouched) ->min_delta_ns > and ->max_delta_ns. As soon as this has changed, a followup patch will > purge the initialization of ->min_delta_ns and ->max_delta_ns from this > driver. > > Signed-off-by: Nicolai Stange Reviewed-by: Boris Ostrovsky
Re: [PATCH] x86/xen/time: set ->min_delta_ticks and ->max_delta_ticks
On 30/03/17 22:06, Nicolai Stange wrote: > In preparation for making the clockevents core NTP correction aware, > all clockevent device drivers must set ->min_delta_ticks and > ->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a > clockevent device's rate is going to change dynamically and thus, the > ratio of ns to ticks ceases to stay invariant. > > Make the x86 arch's xen clockevent driver initialize these fields properly. > > This patch alone doesn't introduce any change in functionality as the > clockevents core still looks exclusively at the (untouched) ->min_delta_ns > and ->max_delta_ns. As soon as this has changed, a followup patch will > purge the initialization of ->min_delta_ns and ->max_delta_ns from this > driver. > > Signed-off-by: Nicolai Stange Shall I carry this patch through the Xen tree or will it be processed via the tip tree? I'm fine with both variants. Juergen > --- > > Notes: > This prerequisite patch is part of a larger effort to feed NTP > corrections into the clockevent devices' frequencies and thus > avoiding their notion of time to diverge from the system's > one. If you're interested, the current state of the whole series > can be found at [1]. > > If you haven't got any objections and these prerequisites get > merged by 4.12 everywhere, I'll proceed with the remainder of > this series in 4.13. > > Applicable to next-20170324 as well as to John' Stultz tree [2]. > > [1] > git://nicst.de/linux.git cev-freq-adj.v10.fortglx-4.12-time > > https://nicst.de/git/?p=linux.git;a=shortlog;h=refs/heads/cev-freq-adj.v10.fortglx-4.12-time > > [2] > https://git.linaro.org/people/john.stultz/linux.git fortglx/4.12/time > > arch/x86/xen/time.c | 4 > 1 file changed, 4 insertions(+) > > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > index 1e69956d7852..7a3089285c59 100644 > --- a/arch/x86/xen/time.c > +++ b/arch/x86/xen/time.c > @@ -209,7 +209,9 @@ static const struct clock_event_device > xen_timerop_clockevent = { > .features = CLOCK_EVT_FEAT_ONESHOT, > > .max_delta_ns = 0x, > + .max_delta_ticks= 0x, > .min_delta_ns = TIMER_SLOP, > + .min_delta_ticks= TIMER_SLOP, > > .mult = 1, > .shift = 0, > @@ -268,7 +270,9 @@ static const struct clock_event_device > xen_vcpuop_clockevent = { > .features = CLOCK_EVT_FEAT_ONESHOT, > > .max_delta_ns = 0x, > + .max_delta_ticks = 0x, > .min_delta_ns = TIMER_SLOP, > + .min_delta_ticks = TIMER_SLOP, > > .mult = 1, > .shift = 0, >