nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

timekeeping: Remove boot time specific code

Browse source 
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 <tglx@linutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Easton <kevin@guarana.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20180301165150.236279497@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Thomas Gleixner 2018-03-01 17:33:35 +01:00 committed by Ingo Molnar
parent f2d6fdbfd2
commit d6c7270e91
2 changed files with 17 additions and 56 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

42
include/linux/timekeeping.h
View file

@ -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());

31
kernel/time/timekeeping.c
View file

@ -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,
};