From d6c7270e913db75ca5fdc79915ba780e97ae2857 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 1 Mar 2018 17:33:35 +0100 Subject: [PATCH] timekeeping: Remove boot time specific code Now that the MONOTONIC and BOOTTIME clocks are the same, remove all the special handling from timekeeping. Keep wrappers for the existing users of the *boot* timekeeper interfaces. Signed-off-by: Thomas Gleixner Cc: Dmitry Torokhov Cc: John Stultz Cc: Jonathan Corbet Cc: Kevin Easton Cc: Linus Torvalds Cc: Mark Salyzyn Cc: Michael Kerrisk Cc: Peter Zijlstra Cc: Petr Mladek Cc: Prarit Bhargava Cc: Sergey Senozhatsky Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20180301165150.236279497@linutronix.de Signed-off-by: Ingo Molnar --- include/linux/timekeeping.h | 42 +++++++++++++++---------------------- kernel/time/timekeeping.c | 31 --------------------------- 2 files changed, 17 insertions(+), 56 deletions(-) diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h index 440b1935d3a5..abb396731332 100644 --- a/include/linux/timekeeping.h +++ b/include/linux/timekeeping.h @@ -38,15 +38,19 @@ extern int __getnstimeofday64(struct timespec64 *tv); extern void getnstimeofday64(struct timespec64 *tv); extern void getboottime64(struct timespec64 *ts); -#define ktime_get_real_ts64(ts) getnstimeofday64(ts) +#define ktime_get_real_ts64(ts) getnstimeofday64(ts) + +/* Clock BOOTTIME compatibility wrappers */ +static inline void get_monotonic_boottime64(struct timespec64 *ts) +{ + ktime_get_ts64(ts); +} /* * ktime_t based interfaces */ - enum tk_offsets { TK_OFFS_REAL, - TK_OFFS_BOOT, TK_OFFS_TAI, TK_OFFS_MAX, }; @@ -57,6 +61,10 @@ extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs); extern ktime_t ktime_get_raw(void); extern u32 ktime_get_resolution_ns(void); +/* Clock BOOTTIME compatibility wrappers */ +static inline ktime_t ktime_get_boottime(void) { return ktime_get(); } +static inline u64 ktime_get_boot_ns(void) { return ktime_get(); } + /** * ktime_get_real - get the real (wall-) time in ktime_t format */ @@ -65,17 +73,6 @@ static inline ktime_t ktime_get_real(void) return ktime_get_with_offset(TK_OFFS_REAL); } -/** - * ktime_get_boottime - Returns monotonic time since boot in ktime_t format - * - * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the - * time spent in suspend. - */ -static inline ktime_t ktime_get_boottime(void) -{ - return ktime_get_with_offset(TK_OFFS_BOOT); -} - /** * ktime_get_clocktai - Returns the TAI time of day in ktime_t format */ @@ -102,11 +99,6 @@ static inline u64 ktime_get_real_ns(void) return ktime_to_ns(ktime_get_real()); } -static inline u64 ktime_get_boot_ns(void) -{ - return ktime_to_ns(ktime_get_boottime()); -} - static inline u64 ktime_get_tai_ns(void) { return ktime_to_ns(ktime_get_clocktai()); @@ -119,17 +111,17 @@ static inline u64 ktime_get_raw_ns(void) extern u64 ktime_get_mono_fast_ns(void); extern u64 ktime_get_raw_fast_ns(void); -extern u64 ktime_get_boot_fast_ns(void); extern u64 ktime_get_real_fast_ns(void); +/* Clock BOOTTIME compatibility wrappers */ +static inline u64 ktime_get_boot_fast_ns(void) +{ + return ktime_get_mono_fast_ns(); +} + /* * timespec64 interfaces utilizing the ktime based ones */ -static inline void get_monotonic_boottime64(struct timespec64 *ts) -{ - *ts = ktime_to_timespec64(ktime_get_boottime()); -} - static inline void timekeeping_clocktai64(struct timespec64 *ts) { *ts = ktime_to_timespec64(ktime_get_clocktai()); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index b509fe7acd64..8355c8803282 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -473,36 +473,6 @@ u64 ktime_get_raw_fast_ns(void) } EXPORT_SYMBOL_GPL(ktime_get_raw_fast_ns); -/** - * ktime_get_boot_fast_ns - NMI safe and fast access to boot clock. - * - * To keep it NMI safe since we're accessing from tracing, we're not using a - * separate timekeeper with updates to monotonic clock and boot offset - * protected with seqlocks. This has the following minor side effects: - * - * (1) Its possible that a timestamp be taken after the boot offset is updated - * but before the timekeeper is updated. If this happens, the new boot offset - * is added to the old timekeeping making the clock appear to update slightly - * earlier: - * CPU 0 CPU 1 - * timekeeping_inject_sleeptime64() - * __timekeeping_inject_sleeptime(tk, delta); - * timestamp(); - * timekeeping_update(tk, TK_CLEAR_NTP...); - * - * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be - * partially updated. Since the tk->offs_boot update is a rare event, this - * should be a rare occurrence which postprocessing should be able to handle. - */ -u64 notrace ktime_get_boot_fast_ns(void) -{ - struct timekeeper *tk = &tk_core.timekeeper; - - return (ktime_get_mono_fast_ns() + ktime_to_ns(tk->offs_boot)); -} -EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns); - - /* * See comment for __ktime_get_fast_ns() vs. timestamp ordering */ @@ -794,7 +764,6 @@ EXPORT_SYMBOL_GPL(ktime_get_resolution_ns); static ktime_t *offsets[TK_OFFS_MAX] = { [TK_OFFS_REAL] = &tk_core.timekeeper.offs_real, - [TK_OFFS_BOOT] = &tk_core.timekeeper.offs_boot, [TK_OFFS_TAI] = &tk_core.timekeeper.offs_tai, };