[PATCH 0/5] time/jiffies changes for tip/timers/core

[PATCH 0/5] time/jiffies changes for tip/timers/core

[John Stultz]

Hey Thomas, Ingo,
	Here's updated time/jiffies patches including Ingo's
feedback for tip/timers/core.

Let me know if there's any further tweaks you'd like to see.

thanks
-john

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>


Catalin Marinas (1):
  jiffies: Allow CLOCK_TICK_RATE to be undefined

John Stultz (4):
  jiffies: Rename ACTHZ to SHIFTED_HZ
  time: Stray newline cleanups
  time: Cleanup offs_real/wall_to_mono and offs_boot/total_sleep_time
    updates
  time: Remove all direct references to timekeeper

 include/linux/jiffies.h   |   29 ++--
 include/linux/timex.h     |    2 +-
 kernel/time/jiffies.c     |    2 +-
 kernel/time/ntp.c         |    2 +-
 kernel/time/timekeeping.c |  373 +++++++++++++++++++++++++--------------------
 5 files changed, 226 insertions(+), 182 deletions(-)

-- 
1.7.9.5

[PATCH 1/5] jiffies: Allow CLOCK_TICK_RATE to be undefined

[John Stultz]

From: Catalin Marinas <catalin.marinas@arm.com>

CLOCK_TICK_RATE is a legacy constant that defines the timer
device's granularity. On hardware with particularly coarse
granularity, this constant is used to reduce accumulated
time error when using jiffies as a clocksource, by calculating
the hardware's actual tick length rather then just assuming
it is 1sec/HZ.

However, for the most part this is unnecessary, as most modern
systems don't use jiffies for their clocksource, and their
tick device is sufficiently fine grained to avoid major error.

Thus, this patch allows an architecture to not define
CLOCK_TICK_RATE, in which case ACTHZ defaults to (HZ << 8).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[jstultz: commit log & intention tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 include/linux/jiffies.h |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 265e2c3..7d24466 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -39,9 +39,6 @@
 # error Invalid value of HZ.
 #endif
 
-/* LATCH is used in the interval timer and ftape setup. */
-#define LATCH  ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
-
 /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
  * improve accuracy by shifting LSH bits, hence calculating:
  *     (NOM << LSH) / DEN
@@ -54,8 +51,15 @@
 #define SH_DIV(NOM,DEN,LSH) (   (((NOM) / (DEN)) << (LSH))              \
                              + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
 
+#ifdef CLOCK_TICK_RATE
+/* LATCH is used in the interval timer and ftape setup. */
+# define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
+
 /* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-#define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8))
+# define ACTHZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+#else
+# define ACTHZ (HZ << 8)
+#endif
 
 /* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
 #define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))
-- 
1.7.9.5

[PATCH 2/5] jiffies: Rename ACTHZ to SHIFTED_HZ

[John Stultz]

Ingo noted that ACTHZ is a confusing name, and requested it
be renamed, so this patch renames ACTHZ to SHIFTED_HZ to
better describe it.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 include/linux/jiffies.h |   21 +++++++++++++--------
 include/linux/timex.h   |    2 +-
 kernel/time/jiffies.c   |    2 +-
 kernel/time/ntp.c       |    2 +-
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 7d24466..8268054 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -55,21 +55,26 @@
 /* LATCH is used in the interval timer and ftape setup. */
 # define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
 
-/* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-# define ACTHZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+/*
+ * HZ is the requested value. However the CLOCK_TICK_RATE may not allow
+ * for exactly HZ. So SHIFTED_HZ is high res HZ ("<< 8" is for accuracy)
+ */
+# define SHIFTED_HZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
 #else
-# define ACTHZ (HZ << 8)
+# define SHIFTED_HZ (HZ << 8)
 #endif
 
-/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
-#define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))
+/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
+#define TICK_NSEC (SH_DIV(1000000UL * 1000, SHIFTED_HZ, 8))
 
 /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
 #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
 
-/* TICK_USEC_TO_NSEC is the time between ticks in nsec assuming real ACTHZ and	*/
-/* a value TUSEC for TICK_USEC (can be set bij adjtimex)		*/
-#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV (TUSEC * USER_HZ * 1000, ACTHZ, 8))
+/*
+ * TICK_USEC_TO_NSEC is the time between ticks in nsec assuming SHIFTED_HZ and
+ * a value TUSEC for TICK_USEC (can be set bij adjtimex)
+ */
+#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV(TUSEC * USER_HZ * 1000, SHIFTED_HZ, 8))
 
 /* some arch's have a small-data section that can be accessed register-relative
  * but that can only take up to, say, 4-byte variables. jiffies being part of
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 99bc88b..7c5ceb2 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -232,7 +232,7 @@ struct timex {
  * estimated error = NTP dispersion.
  */
 extern unsigned long tick_usec;		/* USER_HZ period (usec) */
-extern unsigned long tick_nsec;		/* ACTHZ          period (nsec) */
+extern unsigned long tick_nsec;		/* SHIFTED_HZ period (nsec) */
 
 extern void ntp_init(void);
 extern void ntp_clear(void);
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a470154..46da053 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -37,7 +37,7 @@
  * requested HZ value. It is also not recommended
  * for "tick-less" systems.
  */
-#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/SHIFTED_HZ))
 
 /* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
  * conversion, the .shift value could be zero. However
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index b7fbadc..24174b4 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -28,7 +28,7 @@ DEFINE_SPINLOCK(ntp_lock);
 /* USER_HZ period (usecs): */
 unsigned long			tick_usec = TICK_USEC;
 
-/* ACTHZ period (nsecs): */
+/* SHIFTED_HZ period (nsecs): */
 unsigned long			tick_nsec;
 
 static u64			tick_length;
-- 
1.7.9.5

[PATCH 3/5] time: Stray newline cleanups

[John Stultz]

Ingo noted inconsistent newline usage between functions.
This patch cleans those up.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 kernel/time/timekeeping.c |   10 ----------
 1 file changed, 10 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f045cc5..8d8636f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -239,7 +239,6 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 	update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
 
-
 /**
  * timekeeping_forward_now - update clock to the current time
  *
@@ -436,7 +435,6 @@ int do_settimeofday(const struct timespec *tv)
 }
 EXPORT_SYMBOL(do_settimeofday);
 
-
 /**
  * timekeeping_inject_offset - Adds or subtracts from the current time.
  * @tv:		pointer to the timespec variable containing the offset
@@ -550,7 +548,6 @@ void getrawmonotonic(struct timespec *ts)
 }
 EXPORT_SYMBOL(getrawmonotonic);
 
-
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
@@ -683,7 +680,6 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
 	update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
 }
 
-
 /**
  * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
  * @delta: pointer to a timespec delta value
@@ -718,7 +714,6 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 	clock_was_set();
 }
 
-
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
  *
@@ -1003,7 +998,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 
 }
 
-
 /**
  * accumulate_nsecs_to_secs - Accumulates nsecs into secs
  *
@@ -1032,7 +1026,6 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 	}
 }
 
-
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
  *
@@ -1076,7 +1069,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 	return offset;
 }
 
-
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
@@ -1177,7 +1169,6 @@ void getboottime(struct timespec *ts)
 }
 EXPORT_SYMBOL_GPL(getboottime);
 
-
 /**
  * get_monotonic_boottime - Returns monotonic time since boot
  * @ts:		pointer to the timespec to be set
@@ -1358,7 +1349,6 @@ ktime_t ktime_get_monotonic_offset(void)
 }
 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
 
-
 /**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:	number of ticks, that have elapsed since the last call.
-- 
1.7.9.5

[PATCH 4/5] time: Cleanup offs_real/wall_to_mono and offs_boot/total_sleep_time updates

[John Stultz]

For performance reasons, we maintain ktime_t based duplicates of
wall_to_monotonic (offs_real) and total_sleep_time (offs_boot).

Since large problems could occur (such as the resume regression
on 3.5-rc7, or the leapsecond hrtimer issue) if these value pairs
were to be inconsistently updated, this patch this cleans up how
we modify these value pairs to ensure we are always consistent.

As a side-effect this is also more efficient as we only
caulculate the duplicate values when they are changed,
rather then every update_wall_time call.

This also provides WARN_ONs to detect if future changes break
the invariants.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 kernel/time/timekeeping.c |   91 +++++++++++++++++++++++++++------------------
 1 file changed, 55 insertions(+), 36 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 8d8636f..c4061f5 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -65,14 +65,14 @@ struct timekeeper {
 	 * used instead.
 	 */
 	struct timespec		wall_to_monotonic;
-	/* time spent in suspend */
-	struct timespec		total_sleep_time;
-	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
-	struct timespec		raw_time;
 	/* Offset clock monotonic -> clock realtime */
 	ktime_t			offs_real;
+	/* time spent in suspend */
+	struct timespec		total_sleep_time;
 	/* Offset clock monotonic -> clock boottime */
 	ktime_t			offs_boot;
+	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+	struct timespec		raw_time;
 	/* Seqlock for all timekeeper values */
 	seqlock_t		lock;
 };
@@ -117,6 +117,32 @@ static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
 	tk->xtime_nsec += ts->tv_nsec << tk->shift;
 }
 
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+	struct timespec tmp;
+
+	/*
+	 * Verify consistency of: offset_real = -wall_to_monotonic
+	 * before modifying anything
+	 */
+	set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+					-tk->wall_to_monotonic.tv_nsec);
+	WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+	tk->wall_to_monotonic = wtm;
+	set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+	tk->offs_real = timespec_to_ktime(tmp);
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+	/* Verify consistency before modifying */
+	WARN_ON_ONCE(tk->offs_boot.tv64 !=
+				timespec_to_ktime(tk->total_sleep_time).tv64);
+
+	tk->total_sleep_time = t;
+	tk->offs_boot = timespec_to_ktime(t);
+}
+
 /**
  * timekeeper_setup_internals - Set up internals to use clocksource clock.
  *
@@ -217,14 +243,6 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 	return nsec + arch_gettimeoffset();
 }
 
-static void update_rt_offset(struct timekeeper *tk)
-{
-	struct timespec tmp, *wtm = &tk->wall_to_monotonic;
-
-	set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
-	tk->offs_real = timespec_to_ktime(tmp);
-}
-
 /* must hold write on timekeeper.lock */
 static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 {
@@ -234,7 +252,6 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 		tk->ntp_error = 0;
 		ntp_clear();
 	}
-	update_rt_offset(tk);
 	xt = tk_xtime(tk);
 	update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
@@ -419,8 +436,8 @@ int do_settimeofday(const struct timespec *tv)
 	ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
 	ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-	timekeeper.wall_to_monotonic =
-			timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
+	tk_set_wall_to_mono(&timekeeper,
+			timespec_sub(timekeeper.wall_to_monotonic, ts_delta));
 
 	tk_set_xtime(&timekeeper, tv);
 
@@ -454,8 +471,8 @@ int timekeeping_inject_offset(struct timespec *ts)
 
 
 	tk_xtime_add(&timekeeper, ts);
-	timekeeper.wall_to_monotonic =
-				timespec_sub(timekeeper.wall_to_monotonic, *ts);
+	tk_set_wall_to_mono(&timekeeper,
+			timespec_sub(timekeeper.wall_to_monotonic, *ts));
 
 	timekeeping_update(&timekeeper, true);
 
@@ -621,7 +638,7 @@ void __init timekeeping_init(void)
 {
 	struct clocksource *clock;
 	unsigned long flags;
-	struct timespec now, boot;
+	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
 	read_boot_clock(&boot);
@@ -642,23 +659,19 @@ void __init timekeeping_init(void)
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
 		boot = tk_xtime(&timekeeper);
 
-	set_normalized_timespec(&timekeeper.wall_to_monotonic,
-				-boot.tv_sec, -boot.tv_nsec);
-	update_rt_offset(&timekeeper);
-	timekeeper.total_sleep_time.tv_sec = 0;
-	timekeeper.total_sleep_time.tv_nsec = 0;
+	set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+	tk_set_wall_to_mono(&timekeeper, tmp);
+
+	tmp.tv_sec = 0;
+	tmp.tv_nsec = 0;
+	tk_set_sleep_time(&timekeeper, tmp);
+
 	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 }
 
 /* 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
@@ -674,10 +687,9 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
 					"sleep delta value!\n");
 		return;
 	}
-
 	tk_xtime_add(tk, delta);
-	tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
-	update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+	tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
 }
 
 /**
@@ -1018,11 +1030,18 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 
 		/* Figure out if its a leap sec and apply if needed */
 		leap = second_overflow(tk->xtime_sec);
-		tk->xtime_sec += leap;
-		tk->wall_to_monotonic.tv_sec -= leap;
-		if (leap)
-			clock_was_set_delayed();
+		if (unlikely(leap)) {
+			struct timespec ts;
+
+			tk->xtime_sec += leap;
 
+			ts.tv_sec = leap;
+			ts.tv_nsec = 0;
+			tk_set_wall_to_mono(tk,
+				timespec_sub(tk->wall_to_monotonic, ts));
+
+			clock_was_set_delayed();
+		}
 	}
 }
 
-- 
1.7.9.5

[PATCH 5/5] time: Remove all direct references to timekeeper

[John Stultz]

Ingo noted that the numerous timekeeper.value references made
the timekeeping code ugly and caused many long lines that
had to be broken up. He recommended replacing timekeeper.value
references with tk->value.

This patch provides a local tk value for all top level time
functions and sets it to &timekeeper. Then all timekeeper
access is done via a tk pointer.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 kernel/time/timekeeping.c |  282 +++++++++++++++++++++++++--------------------
 1 file changed, 154 insertions(+), 128 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index c4061f5..52e2bd1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -293,18 +293,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
  */
 void getnstimeofday(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs = 0;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -312,19 +313,18 @@ EXPORT_SYMBOL(getnstimeofday);
 
 ktime_t ktime_get(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned int seq;
 	s64 secs, nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		secs = timekeeper.xtime_sec +
-				timekeeper.wall_to_monotonic.tv_sec;
-		nsecs = timekeeping_get_ns(&timekeeper) +
-				timekeeper.wall_to_monotonic.tv_nsec;
+		seq = read_seqbegin(&tk->lock);
+		secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+		nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 	/*
 	 * Use ktime_set/ktime_add_ns to create a proper ktime on
 	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -343,18 +343,19 @@ EXPORT_SYMBOL_GPL(ktime_get);
  */
 void ktime_get_ts(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec tomono;
 	unsigned int seq;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-		tomono = timekeeper.wall_to_monotonic;
+		seq = read_seqbegin(&tk->lock);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
 				ts->tv_nsec + tomono.tv_nsec);
@@ -374,22 +375,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
  */
 void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs_raw, nsecs_real;
 
 	WARN_ON_ONCE(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		*ts_raw = timekeeper.raw_time;
-		ts_real->tv_sec = timekeeper.xtime_sec;
+		*ts_raw = tk->raw_time;
+		ts_real->tv_sec = tk->xtime_sec;
 		ts_real->tv_nsec = 0;
 
-		nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
-		nsecs_real = timekeeping_get_ns(&timekeeper);
+		nsecs_raw = timekeeping_get_ns_raw(tk);
+		nsecs_real = timekeeping_get_ns(tk);
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts_raw, nsecs_raw);
 	timespec_add_ns(ts_real, nsecs_real);
@@ -422,28 +424,28 @@ EXPORT_SYMBOL(do_gettimeofday);
  */
 int do_settimeofday(const struct timespec *tv)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec ts_delta, xt;
 	unsigned long flags;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
-	xt = tk_xtime(&timekeeper);
+	xt = tk_xtime(tk);
 	ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
 	ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-	tk_set_wall_to_mono(&timekeeper,
-			timespec_sub(timekeeper.wall_to_monotonic, ts_delta));
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
 
-	tk_set_xtime(&timekeeper, tv);
+	tk_set_xtime(tk, tv);
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -460,23 +462,23 @@ EXPORT_SYMBOL(do_settimeofday);
  */
 int timekeeping_inject_offset(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 
 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
 
-	tk_xtime_add(&timekeeper, ts);
-	tk_set_wall_to_mono(&timekeeper,
-			timespec_sub(timekeeper.wall_to_monotonic, *ts));
+	tk_xtime_add(tk, ts);
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -492,23 +494,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
  */
 static int change_clocksource(void *data)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *new, *old;
 	unsigned long flags;
 
 	new = (struct clocksource *) data;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 	if (!new->enable || new->enable(new) == 0) {
-		old = timekeeper.clock;
-		tk_setup_internals(&timekeeper, new);
+		old = tk->clock;
+		tk_setup_internals(tk, new);
 		if (old->disable)
 			old->disable(old);
 	}
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	return 0;
 }
@@ -522,7 +525,9 @@ static int change_clocksource(void *data)
  */
 void timekeeping_notify(struct clocksource *clock)
 {
-	if (timekeeper.clock == clock)
+	struct timekeeper *tk = &timekeeper;
+
+	if (tk->clock == clock)
 		return;
 	stop_machine(change_clocksource, clock, NULL);
 	tick_clock_notify();
@@ -551,15 +556,16 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  */
 void getrawmonotonic(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		nsecs = timekeeping_get_ns_raw(&timekeeper);
-		*ts = timekeeper.raw_time;
+		seq = read_seqbegin(&tk->lock);
+		nsecs = timekeeping_get_ns_raw(tk);
+		*ts = tk->raw_time;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -570,15 +576,16 @@ EXPORT_SYMBOL(getrawmonotonic);
  */
 int timekeeping_valid_for_hres(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	int ret;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+		ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	return ret;
 }
@@ -588,15 +595,16 @@ int timekeeping_valid_for_hres(void)
  */
 u64 timekeeping_max_deferment(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ret = timekeeper.clock->max_idle_ns;
+		ret = tk->clock->max_idle_ns;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	return ret;
 }
@@ -636,6 +644,7 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
  */
 void __init timekeeping_init(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *clock;
 	unsigned long flags;
 	struct timespec now, boot, tmp;
@@ -643,30 +652,30 @@ void __init timekeeping_init(void)
 	read_persistent_clock(&now);
 	read_boot_clock(&boot);
 
-	seqlock_init(&timekeeper.lock);
+	seqlock_init(&tk->lock);
 
 	ntp_init();
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 	clock = clocksource_default_clock();
 	if (clock->enable)
 		clock->enable(clock);
-	tk_setup_internals(&timekeeper, clock);
+	tk_setup_internals(tk, clock);
 
-	tk_set_xtime(&timekeeper, &now);
-	timekeeper.raw_time.tv_sec = 0;
-	timekeeper.raw_time.tv_nsec = 0;
+	tk_set_xtime(tk, &now);
+	tk->raw_time.tv_sec = 0;
+	tk->raw_time.tv_nsec = 0;
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
-		boot = tk_xtime(&timekeeper);
+		boot = tk_xtime(tk);
 
 	set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
-	tk_set_wall_to_mono(&timekeeper, tmp);
+	tk_set_wall_to_mono(tk, tmp);
 
 	tmp.tv_sec = 0;
 	tmp.tv_nsec = 0;
-	tk_set_sleep_time(&timekeeper, tmp);
+	tk_set_sleep_time(tk, tmp);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 }
 
 /* time in seconds when suspend began */
@@ -704,6 +713,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
  */
 void timekeeping_inject_sleeptime(struct timespec *delta)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec ts;
 
@@ -712,15 +722,15 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
 		return;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
-	__timekeeping_inject_sleeptime(&timekeeper, delta);
+	__timekeeping_inject_sleeptime(tk, delta);
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -735,6 +745,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
  */
 static void timekeeping_resume(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec ts;
 
@@ -742,18 +753,18 @@ static void timekeeping_resume(void)
 
 	clocksource_resume();
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
 	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
 		ts = timespec_sub(ts, timekeeping_suspend_time);
-		__timekeeping_inject_sleeptime(&timekeeper, &ts);
+		__timekeeping_inject_sleeptime(tk, &ts);
 	}
 	/* re-base the last cycle value */
-	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
-	timekeeper.ntp_error = 0;
+	tk->clock->cycle_last = tk->clock->read(tk->clock);
+	tk->ntp_error = 0;
 	timekeeping_suspended = 0;
-	timekeeping_update(&timekeeper, false);
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	timekeeping_update(tk, false);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	touch_softlockup_watchdog();
 
@@ -765,14 +776,15 @@ static void timekeeping_resume(void)
 
 static int timekeeping_suspend(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec		delta, delta_delta;
 	static struct timespec	old_delta;
 
 	read_persistent_clock(&timekeeping_suspend_time);
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
-	timekeeping_forward_now(&timekeeper);
+	write_seqlock_irqsave(&tk->lock, flags);
+	timekeeping_forward_now(tk);
 	timekeeping_suspended = 1;
 
 	/*
@@ -781,7 +793,7 @@ static int timekeeping_suspend(void)
 	 * try to compensate so the difference in system time
 	 * and persistent_clock time stays close to constant.
 	 */
-	delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
+	delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
 	delta_delta = timespec_sub(delta, old_delta);
 	if (abs(delta_delta.tv_sec)  >= 2) {
 		/*
@@ -794,7 +806,7 @@ static int timekeeping_suspend(void)
 		timekeeping_suspend_time =
 			timespec_add(timekeeping_suspend_time, delta_delta);
 	}
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
 	clocksource_suspend();
@@ -905,7 +917,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 		 * the error. This causes the likely below to be unlikely.
 		 *
 		 * The proper fix is to avoid rounding up by using
-		 * the high precision timekeeper.xtime_nsec instead of
+		 * the high precision tk->xtime_nsec instead of
 		 * xtime.tv_nsec everywhere. Fixing this will take some
 		 * time.
 		 */
@@ -1095,21 +1107,22 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 static void update_wall_time(void)
 {
 	struct clocksource *clock;
+	struct timekeeper *tk = &timekeeper;
 	cycle_t offset;
 	int shift = 0, maxshift;
 	unsigned long flags;
 	s64 remainder;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
 		goto out;
 
-	clock = timekeeper.clock;
+	clock = tk->clock;
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-	offset = timekeeper.cycle_interval;
+	offset = tk->cycle_interval;
 #else
 	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
@@ -1122,19 +1135,19 @@ static void update_wall_time(void)
 	 * chunk in one go, and then try to consume the next smaller
 	 * doubled multiple.
 	 */
-	shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+	shift = ilog2(offset) - ilog2(tk->cycle_interval);
 	shift = max(0, shift);
 	/* Bound shift to one less than what overflows tick_length */
 	maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
 	shift = min(shift, maxshift);
-	while (offset >= timekeeper.cycle_interval) {
-		offset = logarithmic_accumulation(&timekeeper, offset, shift);
-		if(offset < timekeeper.cycle_interval<<shift)
+	while (offset >= tk->cycle_interval) {
+		offset = logarithmic_accumulation(tk, offset, shift);
+		if (offset < tk->cycle_interval<<shift)
 			shift--;
 	}
 
 	/* correct the clock when NTP error is too big */
-	timekeeping_adjust(&timekeeper, offset);
+	timekeeping_adjust(tk, offset);
 
 
 	/*
@@ -1146,21 +1159,21 @@ static void update_wall_time(void)
 	* the vsyscall implementations are converted to use xtime_nsec
 	* (shifted nanoseconds), this can be killed.
 	*/
-	remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
-	timekeeper.xtime_nsec -= remainder;
-	timekeeper.xtime_nsec += 1 << timekeeper.shift;
-	timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
+	remainder = tk->xtime_nsec & ((1 << tk->shift) - 1);
+	tk->xtime_nsec -= remainder;
+	tk->xtime_nsec += 1 << tk->shift;
+	tk->ntp_error += remainder << tk->ntp_error_shift;
 
 	/*
 	 * Finally, make sure that after the rounding
 	 * xtime_nsec isn't larger than NSEC_PER_SEC
 	 */
-	accumulate_nsecs_to_secs(&timekeeper);
+	accumulate_nsecs_to_secs(tk);
 
-	timekeeping_update(&timekeeper, false);
+	timekeeping_update(tk, false);
 
 out:
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 }
 
@@ -1177,11 +1190,12 @@ out:
  */
 void getboottime(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec boottime = {
-		.tv_sec = timekeeper.wall_to_monotonic.tv_sec +
-				timekeeper.total_sleep_time.tv_sec,
-		.tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
-				timekeeper.total_sleep_time.tv_nsec
+		.tv_sec = tk->wall_to_monotonic.tv_sec +
+				tk->total_sleep_time.tv_sec,
+		.tv_nsec = tk->wall_to_monotonic.tv_nsec +
+				tk->total_sleep_time.tv_nsec
 	};
 
 	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
@@ -1199,19 +1213,20 @@ EXPORT_SYMBOL_GPL(getboottime);
  */
 void get_monotonic_boottime(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec tomono, sleep;
 	unsigned int seq;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-		tomono = timekeeper.wall_to_monotonic;
-		sleep = timekeeper.total_sleep_time;
+		seq = read_seqbegin(&tk->lock);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
+		sleep = tk->total_sleep_time;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
 			ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
@@ -1241,31 +1256,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-	*ts = timespec_add(*ts, timekeeper.total_sleep_time);
+	struct timekeeper *tk = &timekeeper;
+
+	*ts = timespec_add(*ts, tk->total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-	return timekeeper.xtime_sec;
+	struct timekeeper *tk = &timekeeper;
+
+	return tk->xtime_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-	return tk_xtime(&timekeeper);
+	struct timekeeper *tk = &timekeeper;
+
+	return tk_xtime(tk);
 }
 
 struct timespec current_kernel_time(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		now = tk_xtime(&timekeeper);
-	} while (read_seqretry(&timekeeper.lock, seq));
+		now = tk_xtime(tk);
+	} while (read_seqretry(&tk->lock, seq));
 
 	return now;
 }
@@ -1273,15 +1295,16 @@ EXPORT_SYMBOL(current_kernel_time);
 
 struct timespec get_monotonic_coarse(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now, mono;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		now = tk_xtime(&timekeeper);
-		mono = timekeeper.wall_to_monotonic;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		now = tk_xtime(tk);
+		mono = tk->wall_to_monotonic;
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
@@ -1310,14 +1333,15 @@ void do_timer(unsigned long ticks)
 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 				struct timespec *wtom, struct timespec *sleep)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		*xtim = tk_xtime(&timekeeper);
-		*wtom = timekeeper.wall_to_monotonic;
-		*sleep = timekeeper.total_sleep_time;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		seq = read_seqbegin(&tk->lock);
+		*xtim = tk_xtime(tk);
+		*wtom = tk->wall_to_monotonic;
+		*sleep = tk->total_sleep_time;
+	} while (read_seqretry(&tk->lock, seq));
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1331,19 +1355,20 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  */
 ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
 {
+	struct timekeeper *tk = &timekeeper;
 	ktime_t now;
 	unsigned int seq;
 	u64 secs, nsecs;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		secs = timekeeper.xtime_sec;
-		nsecs = timekeeping_get_ns(&timekeeper);
+		secs = tk->xtime_sec;
+		nsecs = timekeeping_get_ns(tk);
 
-		*offs_real = timekeeper.offs_real;
-		*offs_boot = timekeeper.offs_boot;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		*offs_real = tk->offs_real;
+		*offs_boot = tk->offs_boot;
+	} while (read_seqretry(&tk->lock, seq));
 
 	now = ktime_add_ns(ktime_set(secs, 0), nsecs);
 	now = ktime_sub(now, *offs_real);
@@ -1356,13 +1381,14 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
  */
 ktime_t ktime_get_monotonic_offset(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	struct timespec wtom;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		wtom = timekeeper.wall_to_monotonic;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		seq = read_seqbegin(&tk->lock);
+		wtom = tk->wall_to_monotonic;
+	} while (read_seqretry(&tk->lock, seq));
 
 	return timespec_to_ktime(wtom);
 }
-- 
1.7.9.5

Re: [PATCH 0/5] time/jiffies changes for tip/timers/core

[Ingo Molnar]

* John Stultz <john.stultz@linaro.org> wrote:

> Hey Thomas, Ingo,
> 	Here's updated time/jiffies patches including Ingo's
> feedback for tip/timers/core.
> 
> Let me know if there's any further tweaks you'd like to see.

The code looks very nice now. I've applied them to -tip and 
pushed them out.

Thanks,

	Ingo

[tip:timers/urgent] time/jiffies: Allow CLOCK_TICK_RATE to be undefined

[tip-bot for Catalin Marinas]

Commit-ID:  a7ea3bbf5d58f4df2265d312f91d5769eabc8144
Gitweb:     http://git.kernel.org/tip/a7ea3bbf5d58f4df2265d312f91d5769eabc8144
Author:     Catalin Marinas <catalin.marinas@arm.com>
AuthorDate: Fri, 27 Jul 2012 14:48:09 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Jul 2012 17:09:12 +0200

time/jiffies: Allow CLOCK_TICK_RATE to be undefined

CLOCK_TICK_RATE is a legacy constant that defines the timer
device's granularity. On hardware with particularly coarse
granularity, this constant is used to reduce accumulated
time error when using jiffies as a clocksource, by calculating
the hardware's actual tick length rather then just assuming
it is 1sec/HZ.

However, for the most part this is unnecessary, as most modern
systems don't use jiffies for their clocksource, and their
tick device is sufficiently fine grained to avoid major error.

Thus, this patch allows an architecture to not define
CLOCK_TICK_RATE, in which case ACTHZ defaults to (HZ << 8).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
[ Commit log & intention tweaks ]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1343414893-45779-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/jiffies.h |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 265e2c3..7d24466 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -39,9 +39,6 @@
 # error Invalid value of HZ.
 #endif
 
-/* LATCH is used in the interval timer and ftape setup. */
-#define LATCH  ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
-
 /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
  * improve accuracy by shifting LSH bits, hence calculating:
  *     (NOM << LSH) / DEN
@@ -54,8 +51,15 @@
 #define SH_DIV(NOM,DEN,LSH) (   (((NOM) / (DEN)) << (LSH))              \
                              + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
 
+#ifdef CLOCK_TICK_RATE
+/* LATCH is used in the interval timer and ftape setup. */
+# define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
+
 /* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-#define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8))
+# define ACTHZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+#else
+# define ACTHZ (HZ << 8)
+#endif
 
 /* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
 #define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))

[tip:timers/urgent] time/jiffies: Rename ACTHZ to SHIFTED_HZ

[tip-bot for John Stultz]

Commit-ID:  02ab20ae38337b99b5c29c81090f594b8fd61283
Gitweb:     http://git.kernel.org/tip/02ab20ae38337b99b5c29c81090f594b8fd61283
Author:     John Stultz <john.stultz@linaro.org>
AuthorDate: Fri, 27 Jul 2012 14:48:10 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Jul 2012 17:09:12 +0200

time/jiffies: Rename ACTHZ to SHIFTED_HZ

Ingo noted that ACTHZ is a confusing name, and requested it
be renamed, so this patch renames ACTHZ to SHIFTED_HZ to
better describe it.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-3-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/jiffies.h |   21 +++++++++++++--------
 include/linux/timex.h   |    2 +-
 kernel/time/jiffies.c   |    2 +-
 kernel/time/ntp.c       |    2 +-
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 7d24466..8268054 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -55,21 +55,26 @@
 /* LATCH is used in the interval timer and ftape setup. */
 # define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
 
-/* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-# define ACTHZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+/*
+ * HZ is the requested value. However the CLOCK_TICK_RATE may not allow
+ * for exactly HZ. So SHIFTED_HZ is high res HZ ("<< 8" is for accuracy)
+ */
+# define SHIFTED_HZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
 #else
-# define ACTHZ (HZ << 8)
+# define SHIFTED_HZ (HZ << 8)
 #endif
 
-/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
-#define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))
+/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
+#define TICK_NSEC (SH_DIV(1000000UL * 1000, SHIFTED_HZ, 8))
 
 /* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
 #define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
 
-/* TICK_USEC_TO_NSEC is the time between ticks in nsec assuming real ACTHZ and	*/
-/* a value TUSEC for TICK_USEC (can be set bij adjtimex)		*/
-#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV (TUSEC * USER_HZ * 1000, ACTHZ, 8))
+/*
+ * TICK_USEC_TO_NSEC is the time between ticks in nsec assuming SHIFTED_HZ and
+ * a value TUSEC for TICK_USEC (can be set bij adjtimex)
+ */
+#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV(TUSEC * USER_HZ * 1000, SHIFTED_HZ, 8))
 
 /* some arch's have a small-data section that can be accessed register-relative
  * but that can only take up to, say, 4-byte variables. jiffies being part of
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 99bc88b..7c5ceb2 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -232,7 +232,7 @@ struct timex {
  * estimated error = NTP dispersion.
  */
 extern unsigned long tick_usec;		/* USER_HZ period (usec) */
-extern unsigned long tick_nsec;		/* ACTHZ          period (nsec) */
+extern unsigned long tick_nsec;		/* SHIFTED_HZ period (nsec) */
 
 extern void ntp_init(void);
 extern void ntp_clear(void);
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a470154..46da053 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -37,7 +37,7 @@
  * requested HZ value. It is also not recommended
  * for "tick-less" systems.
  */
-#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+#define NSEC_PER_JIFFY	((u32)((((u64)NSEC_PER_SEC)<<8)/SHIFTED_HZ))
 
 /* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
  * conversion, the .shift value could be zero. However
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index b7fbadc..24174b4 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -28,7 +28,7 @@ DEFINE_SPINLOCK(ntp_lock);
 /* USER_HZ period (usecs): */
 unsigned long			tick_usec = TICK_USEC;
 
-/* ACTHZ period (nsecs): */
+/* SHIFTED_HZ period (nsecs): */
 unsigned long			tick_nsec;
 
 static u64			tick_length;

[tip:timers/urgent] time: Clean up stray newlines

[tip-bot for John Stultz]

Commit-ID:  d4e3ab384b2343c7074f713ac330f839c38c52ee
Gitweb:     http://git.kernel.org/tip/d4e3ab384b2343c7074f713ac330f839c38c52ee
Author:     John Stultz <john.stultz@linaro.org>
AuthorDate: Fri, 27 Jul 2012 14:48:11 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Jul 2012 17:09:13 +0200

time: Clean up stray newlines

Ingo noted inconsistent newline usage between functions.
This patch cleans those up.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-4-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/time/timekeeping.c |   10 ----------
 1 files changed, 0 insertions(+), 10 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cf364db..05b37a5 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -239,7 +239,6 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 	update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
 
-
 /**
  * timekeeping_forward_now - update clock to the current time
  *
@@ -436,7 +435,6 @@ int do_settimeofday(const struct timespec *tv)
 }
 EXPORT_SYMBOL(do_settimeofday);
 
-
 /**
  * timekeeping_inject_offset - Adds or subtracts from the current time.
  * @tv:		pointer to the timespec variable containing the offset
@@ -550,7 +548,6 @@ void getrawmonotonic(struct timespec *ts)
 }
 EXPORT_SYMBOL(getrawmonotonic);
 
-
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
@@ -683,7 +680,6 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
 	update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
 }
 
-
 /**
  * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
  * @delta: pointer to a timespec delta value
@@ -718,7 +714,6 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 	clock_was_set();
 }
 
-
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
  *
@@ -1003,7 +998,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 
 }
 
-
 /**
  * accumulate_nsecs_to_secs - Accumulates nsecs into secs
  *
@@ -1032,7 +1026,6 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 	}
 }
 
-
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
  *
@@ -1076,7 +1069,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 	return offset;
 }
 
-
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
@@ -1177,7 +1169,6 @@ void getboottime(struct timespec *ts)
 }
 EXPORT_SYMBOL_GPL(getboottime);
 
-
 /**
  * get_monotonic_boottime - Returns monotonic time since boot
  * @ts:		pointer to the timespec to be set
@@ -1358,7 +1349,6 @@ ktime_t ktime_get_monotonic_offset(void)
 }
 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
 
-
 /**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:	number of ticks, that have elapsed since the last call.

[tip:timers/urgent] time: Clean up offs_real/ wall_to_mono and offs_boot/total_sleep_time updates

[tip-bot for John Stultz]

Commit-ID:  6d0ef903e2bda70da124c10d8ad89f2382c87991
Gitweb:     http://git.kernel.org/tip/6d0ef903e2bda70da124c10d8ad89f2382c87991
Author:     John Stultz <john.stultz@linaro.org>
AuthorDate: Fri, 27 Jul 2012 14:48:12 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Jul 2012 17:09:14 +0200

time: Clean up offs_real/wall_to_mono and offs_boot/total_sleep_time updates

For performance reasons, we maintain ktime_t based duplicates of
wall_to_monotonic (offs_real) and total_sleep_time (offs_boot).

Since large problems could occur (such as the resume regression
on 3.5-rc7, or the leapsecond hrtimer issue) if these value
pairs were to be inconsistently updated, this patch this cleans
up how we modify these value pairs to ensure we are always
consistent.

As a side-effect this is also more efficient as we only
caulculate the duplicate values when they are changed,
rather then every update_wall_time call.

This also provides WARN_ONs to detect if future changes break
the invariants.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-5-git-send-email-john.stultz@linaro.org
[ Cleaned up minor style issues. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/time/timekeeping.c |   90 +++++++++++++++++++++++++++------------------
 1 files changed, 54 insertions(+), 36 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 05b37a5..4da6559 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -65,14 +65,14 @@ struct timekeeper {
 	 * used instead.
 	 */
 	struct timespec		wall_to_monotonic;
-	/* time spent in suspend */
-	struct timespec		total_sleep_time;
-	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
-	struct timespec		raw_time;
 	/* Offset clock monotonic -> clock realtime */
 	ktime_t			offs_real;
+	/* time spent in suspend */
+	struct timespec		total_sleep_time;
 	/* Offset clock monotonic -> clock boottime */
 	ktime_t			offs_boot;
+	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+	struct timespec		raw_time;
 	/* Seqlock for all timekeeper values */
 	seqlock_t		lock;
 };
@@ -117,6 +117,31 @@ static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
 	tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
 }
 
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+	struct timespec tmp;
+
+	/*
+	 * Verify consistency of: offset_real = -wall_to_monotonic
+	 * before modifying anything
+	 */
+	set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+					-tk->wall_to_monotonic.tv_nsec);
+	WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+	tk->wall_to_monotonic = wtm;
+	set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+	tk->offs_real = timespec_to_ktime(tmp);
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+	/* Verify consistency before modifying */
+	WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
+
+	tk->total_sleep_time	= t;
+	tk->offs_boot		= timespec_to_ktime(t);
+}
+
 /**
  * timekeeper_setup_internals - Set up internals to use clocksource clock.
  *
@@ -217,14 +242,6 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
 	return nsec + arch_gettimeoffset();
 }
 
-static void update_rt_offset(struct timekeeper *tk)
-{
-	struct timespec tmp, *wtm = &tk->wall_to_monotonic;
-
-	set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
-	tk->offs_real = timespec_to_ktime(tmp);
-}
-
 /* must hold write on timekeeper.lock */
 static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 {
@@ -234,7 +251,6 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 		tk->ntp_error = 0;
 		ntp_clear();
 	}
-	update_rt_offset(tk);
 	xt = tk_xtime(tk);
 	update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
@@ -419,8 +435,8 @@ int do_settimeofday(const struct timespec *tv)
 	ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
 	ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-	timekeeper.wall_to_monotonic =
-			timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
+	tk_set_wall_to_mono(&timekeeper,
+			timespec_sub(timekeeper.wall_to_monotonic, ts_delta));
 
 	tk_set_xtime(&timekeeper, tv);
 
@@ -454,8 +470,8 @@ int timekeeping_inject_offset(struct timespec *ts)
 
 
 	tk_xtime_add(&timekeeper, ts);
-	timekeeper.wall_to_monotonic =
-				timespec_sub(timekeeper.wall_to_monotonic, *ts);
+	tk_set_wall_to_mono(&timekeeper,
+			timespec_sub(timekeeper.wall_to_monotonic, *ts));
 
 	timekeeping_update(&timekeeper, true);
 
@@ -621,7 +637,7 @@ void __init timekeeping_init(void)
 {
 	struct clocksource *clock;
 	unsigned long flags;
-	struct timespec now, boot;
+	struct timespec now, boot, tmp;
 
 	read_persistent_clock(&now);
 	read_boot_clock(&boot);
@@ -642,23 +658,19 @@ void __init timekeeping_init(void)
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
 		boot = tk_xtime(&timekeeper);
 
-	set_normalized_timespec(&timekeeper.wall_to_monotonic,
-				-boot.tv_sec, -boot.tv_nsec);
-	update_rt_offset(&timekeeper);
-	timekeeper.total_sleep_time.tv_sec = 0;
-	timekeeper.total_sleep_time.tv_nsec = 0;
+	set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+	tk_set_wall_to_mono(&timekeeper, tmp);
+
+	tmp.tv_sec = 0;
+	tmp.tv_nsec = 0;
+	tk_set_sleep_time(&timekeeper, tmp);
+
 	write_sequnlock_irqrestore(&timekeeper.lock, flags);
 }
 
 /* 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
@@ -674,10 +686,9 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
 					"sleep delta value!\n");
 		return;
 	}
-
 	tk_xtime_add(tk, delta);
-	tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
-	update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+	tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
 }
 
 /**
@@ -1018,11 +1029,18 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 
 		/* Figure out if its a leap sec and apply if needed */
 		leap = second_overflow(tk->xtime_sec);
-		tk->xtime_sec += leap;
-		tk->wall_to_monotonic.tv_sec -= leap;
-		if (leap)
-			clock_was_set_delayed();
+		if (unlikely(leap)) {
+			struct timespec ts;
+
+			tk->xtime_sec += leap;
 
+			ts.tv_sec = leap;
+			ts.tv_nsec = 0;
+			tk_set_wall_to_mono(tk,
+				timespec_sub(tk->wall_to_monotonic, ts));
+
+			clock_was_set_delayed();
+		}
 	}
 }
 

[tip:timers/urgent] time: Remove all direct references to timekeeper

[tip-bot for John Stultz]

Commit-ID:  4e250fdde9be50581c7dd5fed88c9b9960615314
Gitweb:     http://git.kernel.org/tip/4e250fdde9be50581c7dd5fed88c9b9960615314
Author:     John Stultz <john.stultz@linaro.org>
AuthorDate: Fri, 27 Jul 2012 14:48:13 -0400
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 31 Jul 2012 17:09:14 +0200

time: Remove all direct references to timekeeper

Ingo noted that the numerous timekeeper.value references made
the timekeeping code ugly and caused many long lines that
had to be broken up. He recommended replacing timekeeper.value
references with tk->value.

This patch provides a local tk value for all top level time
functions and sets it to &timekeeper. Then all timekeeper
access is done via a tk pointer.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1343414893-45779-6-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/time/timekeeping.c |  282 ++++++++++++++++++++++++--------------------
 1 files changed, 154 insertions(+), 128 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 4da6559..2988bc8 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -292,18 +292,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
  */
 void getnstimeofday(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs = 0;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -311,19 +312,18 @@ EXPORT_SYMBOL(getnstimeofday);
 
 ktime_t ktime_get(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned int seq;
 	s64 secs, nsecs;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		secs = timekeeper.xtime_sec +
-				timekeeper.wall_to_monotonic.tv_sec;
-		nsecs = timekeeping_get_ns(&timekeeper) +
-				timekeeper.wall_to_monotonic.tv_nsec;
+		seq = read_seqbegin(&tk->lock);
+		secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+		nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 	/*
 	 * Use ktime_set/ktime_add_ns to create a proper ktime on
 	 * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -342,18 +342,19 @@ EXPORT_SYMBOL_GPL(ktime_get);
  */
 void ktime_get_ts(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec tomono;
 	unsigned int seq;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-		tomono = timekeeper.wall_to_monotonic;
+		seq = read_seqbegin(&tk->lock);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
 				ts->tv_nsec + tomono.tv_nsec);
@@ -373,22 +374,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
  */
 void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs_raw, nsecs_real;
 
 	WARN_ON_ONCE(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		*ts_raw = timekeeper.raw_time;
-		ts_real->tv_sec = timekeeper.xtime_sec;
+		*ts_raw = tk->raw_time;
+		ts_real->tv_sec = tk->xtime_sec;
 		ts_real->tv_nsec = 0;
 
-		nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
-		nsecs_real = timekeeping_get_ns(&timekeeper);
+		nsecs_raw = timekeeping_get_ns_raw(tk);
+		nsecs_real = timekeeping_get_ns(tk);
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts_raw, nsecs_raw);
 	timespec_add_ns(ts_real, nsecs_real);
@@ -421,28 +423,28 @@ EXPORT_SYMBOL(do_gettimeofday);
  */
 int do_settimeofday(const struct timespec *tv)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec ts_delta, xt;
 	unsigned long flags;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
-	xt = tk_xtime(&timekeeper);
+	xt = tk_xtime(tk);
 	ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
 	ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-	tk_set_wall_to_mono(&timekeeper,
-			timespec_sub(timekeeper.wall_to_monotonic, ts_delta));
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
 
-	tk_set_xtime(&timekeeper, tv);
+	tk_set_xtime(tk, tv);
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -459,23 +461,23 @@ EXPORT_SYMBOL(do_settimeofday);
  */
 int timekeeping_inject_offset(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 
 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
 
-	tk_xtime_add(&timekeeper, ts);
-	tk_set_wall_to_mono(&timekeeper,
-			timespec_sub(timekeeper.wall_to_monotonic, *ts));
+	tk_xtime_add(tk, ts);
+	tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -491,23 +493,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
  */
 static int change_clocksource(void *data)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *new, *old;
 	unsigned long flags;
 
 	new = (struct clocksource *) data;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 	if (!new->enable || new->enable(new) == 0) {
-		old = timekeeper.clock;
-		tk_setup_internals(&timekeeper, new);
+		old = tk->clock;
+		tk_setup_internals(tk, new);
 		if (old->disable)
 			old->disable(old);
 	}
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	return 0;
 }
@@ -521,7 +524,9 @@ static int change_clocksource(void *data)
  */
 void timekeeping_notify(struct clocksource *clock)
 {
-	if (timekeeper.clock == clock)
+	struct timekeeper *tk = &timekeeper;
+
+	if (tk->clock == clock)
 		return;
 	stop_machine(change_clocksource, clock, NULL);
 	tick_clock_notify();
@@ -550,15 +555,16 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  */
 void getrawmonotonic(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	s64 nsecs;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		nsecs = timekeeping_get_ns_raw(&timekeeper);
-		*ts = timekeeper.raw_time;
+		seq = read_seqbegin(&tk->lock);
+		nsecs = timekeeping_get_ns_raw(tk);
+		*ts = tk->raw_time;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	timespec_add_ns(ts, nsecs);
 }
@@ -569,15 +575,16 @@ EXPORT_SYMBOL(getrawmonotonic);
  */
 int timekeeping_valid_for_hres(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	int ret;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+		ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	return ret;
 }
@@ -587,15 +594,16 @@ int timekeeping_valid_for_hres(void)
  */
 u64 timekeeping_max_deferment(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	u64 ret;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		ret = timekeeper.clock->max_idle_ns;
+		ret = tk->clock->max_idle_ns;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	return ret;
 }
@@ -635,6 +643,7 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
  */
 void __init timekeeping_init(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct clocksource *clock;
 	unsigned long flags;
 	struct timespec now, boot, tmp;
@@ -642,30 +651,30 @@ void __init timekeeping_init(void)
 	read_persistent_clock(&now);
 	read_boot_clock(&boot);
 
-	seqlock_init(&timekeeper.lock);
+	seqlock_init(&tk->lock);
 
 	ntp_init();
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 	clock = clocksource_default_clock();
 	if (clock->enable)
 		clock->enable(clock);
-	tk_setup_internals(&timekeeper, clock);
+	tk_setup_internals(tk, clock);
 
-	tk_set_xtime(&timekeeper, &now);
-	timekeeper.raw_time.tv_sec = 0;
-	timekeeper.raw_time.tv_nsec = 0;
+	tk_set_xtime(tk, &now);
+	tk->raw_time.tv_sec = 0;
+	tk->raw_time.tv_nsec = 0;
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
-		boot = tk_xtime(&timekeeper);
+		boot = tk_xtime(tk);
 
 	set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
-	tk_set_wall_to_mono(&timekeeper, tmp);
+	tk_set_wall_to_mono(tk, tmp);
 
 	tmp.tv_sec = 0;
 	tmp.tv_nsec = 0;
-	tk_set_sleep_time(&timekeeper, tmp);
+	tk_set_sleep_time(tk, tmp);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 }
 
 /* time in seconds when suspend began */
@@ -703,6 +712,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
  */
 void timekeeping_inject_sleeptime(struct timespec *delta)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec ts;
 
@@ -711,15 +721,15 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 	if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
 		return;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
-	timekeeping_forward_now(&timekeeper);
+	timekeeping_forward_now(tk);
 
-	__timekeeping_inject_sleeptime(&timekeeper, delta);
+	__timekeeping_inject_sleeptime(tk, delta);
 
-	timekeeping_update(&timekeeper, true);
+	timekeeping_update(tk, true);
 
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	/* signal hrtimers about time change */
 	clock_was_set();
@@ -734,6 +744,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
  */
 static void timekeeping_resume(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec ts;
 
@@ -741,18 +752,18 @@ static void timekeeping_resume(void)
 
 	clocksource_resume();
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
 	if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
 		ts = timespec_sub(ts, timekeeping_suspend_time);
-		__timekeeping_inject_sleeptime(&timekeeper, &ts);
+		__timekeeping_inject_sleeptime(tk, &ts);
 	}
 	/* re-base the last cycle value */
-	timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
-	timekeeper.ntp_error = 0;
+	tk->clock->cycle_last = tk->clock->read(tk->clock);
+	tk->ntp_error = 0;
 	timekeeping_suspended = 0;
-	timekeeping_update(&timekeeper, false);
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	timekeeping_update(tk, false);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	touch_softlockup_watchdog();
 
@@ -764,14 +775,15 @@ static void timekeeping_resume(void)
 
 static int timekeeping_suspend(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long flags;
 	struct timespec		delta, delta_delta;
 	static struct timespec	old_delta;
 
 	read_persistent_clock(&timekeeping_suspend_time);
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
-	timekeeping_forward_now(&timekeeper);
+	write_seqlock_irqsave(&tk->lock, flags);
+	timekeeping_forward_now(tk);
 	timekeeping_suspended = 1;
 
 	/*
@@ -780,7 +792,7 @@ static int timekeeping_suspend(void)
 	 * try to compensate so the difference in system time
 	 * and persistent_clock time stays close to constant.
 	 */
-	delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
+	delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
 	delta_delta = timespec_sub(delta, old_delta);
 	if (abs(delta_delta.tv_sec)  >= 2) {
 		/*
@@ -793,7 +805,7 @@ static int timekeeping_suspend(void)
 		timekeeping_suspend_time =
 			timespec_add(timekeeping_suspend_time, delta_delta);
 	}
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
 	clocksource_suspend();
@@ -904,7 +916,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 		 * the error. This causes the likely below to be unlikely.
 		 *
 		 * The proper fix is to avoid rounding up by using
-		 * the high precision timekeeper.xtime_nsec instead of
+		 * the high precision tk->xtime_nsec instead of
 		 * xtime.tv_nsec everywhere. Fixing this will take some
 		 * time.
 		 */
@@ -1094,21 +1106,22 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 static void update_wall_time(void)
 {
 	struct clocksource *clock;
+	struct timekeeper *tk = &timekeeper;
 	cycle_t offset;
 	int shift = 0, maxshift;
 	unsigned long flags;
 	s64 remainder;
 
-	write_seqlock_irqsave(&timekeeper.lock, flags);
+	write_seqlock_irqsave(&tk->lock, flags);
 
 	/* Make sure we're fully resumed: */
 	if (unlikely(timekeeping_suspended))
 		goto out;
 
-	clock = timekeeper.clock;
+	clock = tk->clock;
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-	offset = timekeeper.cycle_interval;
+	offset = tk->cycle_interval;
 #else
 	offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
@@ -1121,19 +1134,19 @@ static void update_wall_time(void)
 	 * chunk in one go, and then try to consume the next smaller
 	 * doubled multiple.
 	 */
-	shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+	shift = ilog2(offset) - ilog2(tk->cycle_interval);
 	shift = max(0, shift);
 	/* Bound shift to one less than what overflows tick_length */
 	maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
 	shift = min(shift, maxshift);
-	while (offset >= timekeeper.cycle_interval) {
-		offset = logarithmic_accumulation(&timekeeper, offset, shift);
-		if(offset < timekeeper.cycle_interval<<shift)
+	while (offset >= tk->cycle_interval) {
+		offset = logarithmic_accumulation(tk, offset, shift);
+		if (offset < tk->cycle_interval<<shift)
 			shift--;
 	}
 
 	/* correct the clock when NTP error is too big */
-	timekeeping_adjust(&timekeeper, offset);
+	timekeeping_adjust(tk, offset);
 
 
 	/*
@@ -1145,21 +1158,21 @@ static void update_wall_time(void)
 	* the vsyscall implementations are converted to use xtime_nsec
 	* (shifted nanoseconds), this can be killed.
 	*/
-	remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
-	timekeeper.xtime_nsec -= remainder;
-	timekeeper.xtime_nsec += 1 << timekeeper.shift;
-	timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
+	remainder = tk->xtime_nsec & ((1 << tk->shift) - 1);
+	tk->xtime_nsec -= remainder;
+	tk->xtime_nsec += 1 << tk->shift;
+	tk->ntp_error += remainder << tk->ntp_error_shift;
 
 	/*
 	 * Finally, make sure that after the rounding
 	 * xtime_nsec isn't larger than NSEC_PER_SEC
 	 */
-	accumulate_nsecs_to_secs(&timekeeper);
+	accumulate_nsecs_to_secs(tk);
 
-	timekeeping_update(&timekeeper, false);
+	timekeeping_update(tk, false);
 
 out:
-	write_sequnlock_irqrestore(&timekeeper.lock, flags);
+	write_sequnlock_irqrestore(&tk->lock, flags);
 
 }
 
@@ -1176,11 +1189,12 @@ out:
  */
 void getboottime(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec boottime = {
-		.tv_sec = timekeeper.wall_to_monotonic.tv_sec +
-				timekeeper.total_sleep_time.tv_sec,
-		.tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
-				timekeeper.total_sleep_time.tv_nsec
+		.tv_sec = tk->wall_to_monotonic.tv_sec +
+				tk->total_sleep_time.tv_sec,
+		.tv_nsec = tk->wall_to_monotonic.tv_nsec +
+				tk->total_sleep_time.tv_nsec
 	};
 
 	set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
@@ -1198,19 +1212,20 @@ EXPORT_SYMBOL_GPL(getboottime);
  */
 void get_monotonic_boottime(struct timespec *ts)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec tomono, sleep;
 	unsigned int seq;
 
 	WARN_ON(timekeeping_suspended);
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		ts->tv_sec = timekeeper.xtime_sec;
-		ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-		tomono = timekeeper.wall_to_monotonic;
-		sleep = timekeeper.total_sleep_time;
+		seq = read_seqbegin(&tk->lock);
+		ts->tv_sec = tk->xtime_sec;
+		ts->tv_nsec = timekeeping_get_ns(tk);
+		tomono = tk->wall_to_monotonic;
+		sleep = tk->total_sleep_time;
 
-	} while (read_seqretry(&timekeeper.lock, seq));
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
 			ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
@@ -1240,31 +1255,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-	*ts = timespec_add(*ts, timekeeper.total_sleep_time);
+	struct timekeeper *tk = &timekeeper;
+
+	*ts = timespec_add(*ts, tk->total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-	return timekeeper.xtime_sec;
+	struct timekeeper *tk = &timekeeper;
+
+	return tk->xtime_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-	return tk_xtime(&timekeeper);
+	struct timekeeper *tk = &timekeeper;
+
+	return tk_xtime(tk);
 }
 
 struct timespec current_kernel_time(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		now = tk_xtime(&timekeeper);
-	} while (read_seqretry(&timekeeper.lock, seq));
+		now = tk_xtime(tk);
+	} while (read_seqretry(&tk->lock, seq));
 
 	return now;
 }
@@ -1272,15 +1294,16 @@ EXPORT_SYMBOL(current_kernel_time);
 
 struct timespec get_monotonic_coarse(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	struct timespec now, mono;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		now = tk_xtime(&timekeeper);
-		mono = timekeeper.wall_to_monotonic;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		now = tk_xtime(tk);
+		mono = tk->wall_to_monotonic;
+	} while (read_seqretry(&tk->lock, seq));
 
 	set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
@@ -1309,14 +1332,15 @@ void do_timer(unsigned long ticks)
 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 				struct timespec *wtom, struct timespec *sleep)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		*xtim = tk_xtime(&timekeeper);
-		*wtom = timekeeper.wall_to_monotonic;
-		*sleep = timekeeper.total_sleep_time;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		seq = read_seqbegin(&tk->lock);
+		*xtim = tk_xtime(tk);
+		*wtom = tk->wall_to_monotonic;
+		*sleep = tk->total_sleep_time;
+	} while (read_seqretry(&tk->lock, seq));
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1330,19 +1354,20 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  */
 ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
 {
+	struct timekeeper *tk = &timekeeper;
 	ktime_t now;
 	unsigned int seq;
 	u64 secs, nsecs;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
+		seq = read_seqbegin(&tk->lock);
 
-		secs = timekeeper.xtime_sec;
-		nsecs = timekeeping_get_ns(&timekeeper);
+		secs = tk->xtime_sec;
+		nsecs = timekeeping_get_ns(tk);
 
-		*offs_real = timekeeper.offs_real;
-		*offs_boot = timekeeper.offs_boot;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		*offs_real = tk->offs_real;
+		*offs_boot = tk->offs_boot;
+	} while (read_seqretry(&tk->lock, seq));
 
 	now = ktime_add_ns(ktime_set(secs, 0), nsecs);
 	now = ktime_sub(now, *offs_real);
@@ -1355,13 +1380,14 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
  */
 ktime_t ktime_get_monotonic_offset(void)
 {
+	struct timekeeper *tk = &timekeeper;
 	unsigned long seq;
 	struct timespec wtom;
 
 	do {
-		seq = read_seqbegin(&timekeeper.lock);
-		wtom = timekeeper.wall_to_monotonic;
-	} while (read_seqretry(&timekeeper.lock, seq));
+		seq = read_seqbegin(&tk->lock);
+		wtom = tk->wall_to_monotonic;
+	} while (read_seqretry(&tk->lock, seq));
 
 	return timespec_to_ktime(wtom);
 }