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Message-Id: <1495856035-6622-5-git-send-email-john.stultz@linaro.org>
Date: Fri, 26 May 2017 20:33:55 -0700
From: John Stultz <john.stultz@...aro.org>
To: lkml <linux-kernel@...r.kernel.org>
Cc: John Stultz <john.stultz@...aro.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...nel.org>,
Miroslav Lichvar <mlichvar@...hat.com>,
Richard Cochran <richardcochran@...il.com>,
Prarit Bhargava <prarit@...hat.com>,
Stephen Boyd <stephen.boyd@...aro.org>,
Kevin Brodsky <kevin.brodsky@....com>,
Will Deacon <will.deacon@....com>,
Daniel Mentz <danielmentz@...gle.com>
Subject: [RFC][PATCH 4/4] time: Clean up CLOCK_MONOTONIC_RAW time handling
Now that we fixed the sub-ns handling for CLOCK_MONOTONIC_RAW,
remove the duplicitive tk->raw_time.tv_nsec, which can be
stored in tk->tkr_raw.xtime_nsec (similarly to how its handled
for monotonic time).
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Miroslav Lichvar <mlichvar@...hat.com>
Cc: Richard Cochran <richardcochran@...il.com>
Cc: Prarit Bhargava <prarit@...hat.com>
Cc: Stephen Boyd <stephen.boyd@...aro.org>
Cc: Kevin Brodsky <kevin.brodsky@....com>
Cc: Will Deacon <will.deacon@....com>
Cc: Daniel Mentz <danielmentz@...gle.com>
Signed-off-by: John Stultz <john.stultz@...aro.org>
---
arch/arm64/kernel/vdso.c | 6 ++---
include/linux/timekeeper_internal.h | 4 ++--
kernel/time/timekeeping.c | 47 ++++++++++++++++++++-----------------
3 files changed, 29 insertions(+), 28 deletions(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index d0cb007..7492d90 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -220,10 +220,8 @@ void update_vsyscall(struct timekeeper *tk)
if (!use_syscall) {
/* tkr_mono.cycle_last == tkr_raw.cycle_last */
vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
- vdso_data->raw_time_sec = tk->raw_time.tv_sec;
- vdso_data->raw_time_nsec = (tk->raw_time.tv_nsec <<
- tk->tkr_raw.shift) +
- tk->tkr_raw.xtime_nsec;
+ vdso_data->raw_time_sec = tk->raw_sec;
+ vdso_data->raw_time_nsec = tk->tkr_raw.xtime_nsec;
vdso_data->xtime_clock_sec = tk->xtime_sec;
vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
vdso_data->cs_mono_mult = tk->tkr_mono.mult;
diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index 528cc86..8abf6df 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -52,7 +52,7 @@ struct tk_read_base {
* @clock_was_set_seq: The sequence number of clock was set events
* @cs_was_changed_seq: The sequence number of clocksource change events
* @next_leap_ktime: CLOCK_MONOTONIC time value of a pending leap-second
- * @raw_time: Monotonic raw base time in timespec64 format
+ * @raw_sec: CLOCK_MONOTONIC_RAW time in seconds
* @cycle_interval: Number of clock cycles in one NTP interval
* @xtime_interval: Number of clock shifted nano seconds in one NTP
* interval.
@@ -94,7 +94,7 @@ struct timekeeper {
unsigned int clock_was_set_seq;
u8 cs_was_changed_seq;
ktime_t next_leap_ktime;
- struct timespec64 raw_time;
+ u64 raw_sec;
/* The following members are for timekeeping internal use */
u64 cycle_interval;
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 35d3ba3..0c3b8c1 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -72,6 +72,10 @@ static inline void tk_normalize_xtime(struct timekeeper *tk)
tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
tk->xtime_sec++;
}
+ while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) {
+ tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
+ tk->raw_sec++;
+ }
}
static inline struct timespec64 tk_xtime(struct timekeeper *tk)
@@ -287,12 +291,14 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
/* if changing clocks, convert xtime_nsec shift units */
if (old_clock) {
int shift_change = clock->shift - old_clock->shift;
- if (shift_change < 0)
+ if (shift_change < 0) {
tk->tkr_mono.xtime_nsec >>= -shift_change;
- else
+ tk->tkr_raw.xtime_nsec >>= -shift_change;
+ } else {
tk->tkr_mono.xtime_nsec <<= shift_change;
+ tk->tkr_raw.xtime_nsec <<= shift_change;
+ }
}
- tk->tkr_raw.xtime_nsec = 0;
tk->tkr_mono.shift = clock->shift;
tk->tkr_raw.shift = clock->shift;
@@ -617,9 +623,6 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
nsec = (u32) tk->wall_to_monotonic.tv_nsec;
tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
- /* Update the monotonic raw base */
- tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time);
-
/*
* The sum of the nanoseconds portions of xtime and
* wall_to_monotonic can be greater/equal one second. Take
@@ -629,6 +632,11 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
if (nsec >= NSEC_PER_SEC)
seconds++;
tk->ktime_sec = seconds;
+
+ /* Update the monotonic raw base */
+ seconds = tk->raw_sec;
+ nsec = (u32)(tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift);
+ tk->tkr_raw.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
}
/* must hold timekeeper_lock */
@@ -670,7 +678,6 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
static void timekeeping_forward_now(struct timekeeper *tk)
{
u64 cycle_now, delta;
- u64 nsec;
cycle_now = tk_clock_read(&tk->tkr_mono);
delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -682,10 +689,13 @@ static void timekeeping_forward_now(struct timekeeper *tk)
/* If arch requires, add in get_arch_timeoffset() */
tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
- tk_normalize_xtime(tk);
- nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift);
- timespec64_add_ns(&tk->raw_time, nsec);
+ tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;
+
+ /* If arch requires, add in get_arch_timeoffset() */
+ tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;
+
+ tk_normalize_xtime(tk);
}
/**
@@ -1371,19 +1381,18 @@ int timekeeping_notify(struct clocksource *clock)
void getrawmonotonic64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
- struct timespec64 ts64;
unsigned long seq;
u64 nsecs;
do {
seq = read_seqcount_begin(&tk_core.seq);
+ ts->tv_sec = tk->raw_sec;
nsecs = timekeeping_get_ns(&tk->tkr_raw);
- ts64 = tk->raw_time;
} while (read_seqcount_retry(&tk_core.seq, seq));
- timespec64_add_ns(&ts64, nsecs);
- *ts = ts64;
+ ts->tv_nsec = 0;
+ timespec64_add_ns(ts, nsecs);
}
EXPORT_SYMBOL(getrawmonotonic64);
@@ -1507,8 +1516,7 @@ void __init timekeeping_init(void)
tk_setup_internals(tk, clock);
tk_set_xtime(tk, &now);
- tk->raw_time.tv_sec = 0;
- tk->raw_time.tv_nsec = 0;
+ tk->raw_sec = 0;
if (boot.tv_sec == 0 && boot.tv_nsec == 0)
boot = tk_xtime(tk);
@@ -2009,17 +2017,12 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
*clock_set |= accumulate_nsecs_to_secs(tk);
/* Accumulate raw time */
- tk->tkr_raw.xtime_nsec += (u64)tk->raw_time.tv_nsec
- << tk->tkr_raw.shift;
tk->tkr_raw.xtime_nsec += tk->raw_interval << shift;
nsecps = (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
while (tk->tkr_raw.xtime_nsec >= nsecps) {
tk->tkr_raw.xtime_nsec -= nsecps;
- tk->raw_time.tv_sec++;
+ tk->raw_sec++;
}
- tk->raw_time.tv_nsec = tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift;
- tk->tkr_raw.xtime_nsec -= (u64)tk->raw_time.tv_nsec
- << tk->tkr_raw.shift;
/* Accumulate error between NTP and clock interval */
tk->ntp_error += tk->ntp_tick << shift;
--
2.7.4
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