From: Rusty Russell <rusty@rustcorp.com.au>
To: Nicolai Stange <nicstange@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>,
linux-kernel@vger.kernel.org,
Nicolai Stange <nicstange@gmail.com>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Paul Bolle <pebolle@tiscali.nl>,
Andy Lutomirski <luto@kernel.org>,
Juergen Gross <jgross@suse.com>,
"Luis R. Rodriguez" <mcgrof@kernel.org>,
lguest@lists.ozlabs.org
Subject: Re: [PATCH] x86/lguest/timer: set ->min_delta_ticks and ->max_delta_ticks
Date: Sun, 02 Apr 2017 11:05:14 +0930 [thread overview]
Message-ID: <874ly7egml.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20170330200341.8097-1-nicstange@gmail.com>
Nicolai Stange <nicstange@gmail.com> writes:
> 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 lguest 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.
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
>
> Signed-off-by: Nicolai Stange <nicstange@gmail.com>
> ---
>
> 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/lguest/boot.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
> index d3289d7e78fa..3e4bf887a246 100644
> --- a/arch/x86/lguest/boot.c
> +++ b/arch/x86/lguest/boot.c
> @@ -994,7 +994,9 @@ static struct clock_event_device lguest_clockevent = {
> .mult = 1,
> .shift = 0,
> .min_delta_ns = LG_CLOCK_MIN_DELTA,
> + .min_delta_ticks = LG_CLOCK_MIN_DELTA,
> .max_delta_ns = LG_CLOCK_MAX_DELTA,
> + .max_delta_ticks = LG_CLOCK_MAX_DELTA,
> };
>
> /*
> --
> 2.12.0
next prev parent reply other threads:[~2017-04-02 23:42 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-26 13:44 [PATCH] x86/apic/timer: set ->min_delta_ticks and ->max_delta_ticks Nicolai Stange
2017-03-30 19:39 ` [PATCH] avr32/time: " Nicolai Stange
2017-04-03 6:42 ` Hans-Christian Noren Egtvedt
2017-03-30 19:41 ` [PATCH] blackfin: time-ts: " Nicolai Stange
2017-03-30 19:42 ` [PATCH] c6x/timer64: " Nicolai Stange
2017-03-30 19:43 ` [PATCH] hexagon/time: " Nicolai Stange
2017-04-03 15:49 ` Richard Kuo
2017-03-30 19:44 ` [PATCH] m68k/coldfire/pit: " Nicolai Stange
2017-03-31 1:10 ` Greg Ungerer
2017-03-30 19:45 ` [PATCH] microblaze/timer: " Nicolai Stange
2017-04-07 13:14 ` Daniel Lezcano
2017-04-16 2:47 ` Nicolai Stange
2017-04-16 9:46 ` Daniel Lezcano
2017-05-29 9:03 ` Michal Simek
2017-03-30 19:47 ` [PATCH] MIPS: clockevent drivers: " Nicolai Stange
2017-04-12 20:10 ` Ralf Baechle
2017-03-30 19:48 ` [PATCH] mn10300/cevt-mn10300: " Nicolai Stange
2017-03-30 19:53 ` [PATCH] powerpc/time: " Nicolai Stange
2017-03-31 3:03 ` Michael Ellerman
2017-03-30 19:54 ` [PATCH] s390/time: " Nicolai Stange
2017-03-30 19:55 ` [PATCH] score/time: " Nicolai Stange
2017-03-30 19:56 ` [PATCH] sparc/time: " Nicolai Stange
2017-04-01 19:18 ` David Miller
2017-03-30 19:57 ` [PATCH] tile/time: " Nicolai Stange
2017-03-30 19:59 ` [PATCH] um/time: " Nicolai Stange
2017-03-30 20:01 ` [PATCH] unicore32/time: " Nicolai Stange
2017-03-31 1:59 ` Xuetao Guan
2017-03-30 20:03 ` [PATCH] x86/lguest/timer: " Nicolai Stange
2017-04-02 1:35 ` Rusty Russell [this message]
2017-03-30 20:04 ` [PATCH] x86/uv/time: " Nicolai Stange
2017-03-30 20:06 ` [PATCH] x86/xen/time: " Nicolai Stange
2017-03-30 22:59 ` Boris Ostrovsky
2017-04-06 9:11 ` Juergen Gross
2017-04-11 5:09 ` Juergen Gross
2017-03-30 20:07 ` [PATCH] clockevents/drivers/dw_apb: " Nicolai Stange
2017-04-07 13:20 ` Daniel Lezcano
2017-03-30 20:08 ` [PATCH] clockevents/drivers/metag: " Nicolai Stange
2017-04-07 13:20 ` Daniel Lezcano
2017-03-30 20:08 ` [PATCH] x86/numachip timer: " Nicolai Stange
2017-04-07 13:21 ` Daniel Lezcano
2017-03-30 20:09 ` [PATCH] clockevents/drivers/sh_cmt: " Nicolai Stange
2017-04-07 13:22 ` Daniel Lezcano
2017-03-30 20:10 ` [PATCH] clockevents/drivers/atlas7: " Nicolai Stange
2017-04-07 13:23 ` Daniel Lezcano
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