Attachment 603551 Details for Bug 836803 – RHEL PATCH 3/7

[patch] RHEL PATCH 3/7

0003-timekeeping-Maintain-ktime_t-based-offsets-for-hrtim.patch (text/plain), 3.61 KB, created by Prarit Bhargava on 2012-08-10 13:56:57 UTC

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Creator: Prarit Bhargava

Created: 2012-08-10 13:56:57 UTC

Size: 3.61 KB

patch

obsolete

>From b2c8e38a6876a4594dfaac8d305c209cd22d903b Mon Sep 17 00:00:00 2001
>From: Prarit Bhargava <prarit@redhat.com>
>Date: Tue, 24 Jul 2012 10:23:25 -0400
>Subject: timekeeping: Maintain ktime_t based offsets for hrtimers
>
>commit 5b9fe759a678e05be4937ddf03d50e950207c1c0
>Author: Thomas Gleixner <tglx@linutronix.de>
>Date:   Tue Jul 10 18:43:21 2012 -0400
>
>    timekeeping: Maintain ktime_t based offsets for hrtimers
>
>    We need to update the hrtimer clock offsets from the hrtimer interrupt
>    context. To avoid conversions from timespec to ktime_t maintain a
>    ktime_t based representation of those offsets in the timekeeper. This
>    puts the conversion overhead into the code which updates the
>    underlying offsets and provides fast accessible values in the hrtimer
>    interrupt.
>
>    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>    Signed-off-by: John Stultz <johnstul@us.ibm.com>
>    Reviewed-by: Ingo Molnar <mingo@kernel.org>
>    Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
>    Acked-by: Prarit Bhargava <prarit@redhat.com>
>    Cc: stable@vger.kernel.org
>    Link: http://lkml.kernel.org/r/1341960205-56738-4-git-send-email-johnstul@us.ibm.com
>    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>---
> kernel/time/timekeeping.c |   25 +++++++++++++++++++++++--
> 1 file changed, 23 insertions(+), 2 deletions(-)
>
>diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
>index 2e7e692..013bafc 100644
>--- a/kernel/time/timekeeping.c
>+++ b/kernel/time/timekeeping.c
>@@ -70,6 +70,12 @@ struct timekeeper {
> 	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
> 	struct timespec raw_time;
> 
>+	/* Offset clock monotonic -> clock realtime */
>+	ktime_t offs_real;
>+
>+	/* Offset clock monotonic -> clock boottime */
>+	ktime_t offs_boot;
>+
> 	/* Seqlock for all timekeeper values */
> 	seqlock_t lock;
> };
>@@ -172,6 +178,14 @@ static inline s64 timekeeping_get_ns_raw(void)
> 	return clocksource_cyc2ns(cycle_delta, clock->mult, clock->shift);
> }
> 
>+static void update_rt_offset(void)
>+{
>+	struct timespec tmp, *wtm = &timekeeper.wall_to_monotonic;
>+
>+	set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
>+	timekeeper.offs_real = timespec_to_ktime(tmp);
>+}
>+
> /* must hold write on timekeeper.lock */
> static void timekeeping_update(bool clearntp)
> {
>@@ -179,6 +193,7 @@ static void timekeeping_update(bool clearntp)
> 		timekeeper.ntp_error = 0;
> 		ntp_clear();
> 	}
>+	update_rt_offset();
> 	update_vsyscall(&timekeeper.xtime, &timekeeper.wall_to_monotonic,
> 			 timekeeper.clock, timekeeper.mult);
> }
>@@ -561,6 +576,7 @@ void __init timekeeping_init(void)
> 	}
> 	set_normalized_timespec(&timekeeper.wall_to_monotonic,
> 				-boot.tv_sec, -boot.tv_nsec);
>+	update_rt_offset();
> 	timekeeper.total_sleep_time.tv_sec = 0;
> 	timekeeper.total_sleep_time.tv_nsec = 0;
> 	write_sequnlock_irqrestore(&timekeeper.lock, flags);
>@@ -569,6 +585,12 @@ void __init timekeeping_init(void)
> /* time in seconds when suspend began */
> static struct timespec timekeeping_suspend_time;
> 
>+static void update_sleep_time(struct timespec t)
>+{
>+	timekeeper.total_sleep_time = t;
>+	timekeeper.offs_boot = timespec_to_ktime(t);
>+}
>+
> /**
>  * __timekeeping_inject_sleeptime - Internal function to add sleep interval
>  * @delta: pointer to a timespec delta value
>@@ -587,8 +609,7 @@ static void __timekeeping_inject_sleeptime(struct timespec *delta)
> 	timekeeper.xtime = timespec_add(timekeeper.xtime, *delta);
> 	timekeeper.wall_to_monotonic =
> 			timespec_sub(timekeeper.wall_to_monotonic, *delta);
>-	timekeeper.total_sleep_time = timespec_add(
>-					timekeeper.total_sleep_time, *delta);
>+	update_sleep_time(timespec_add(timekeeper.total_sleep_time, *delta));
> }
> 
> 
>-- 
>1.7.9.3
>

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