linux/kernel/time
Pavel Tatashin 3eca993740 timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset()
If architecture does not support exact boot time, it is challenging to
estimate boot time without having a reference to the current persistent
clock value. Yet, it cannot read the persistent clock time again, because
this may lead to math discrepancies with the caller of read_boot_clock64()
who have read the persistent clock at a different time.

This is why it is better to provide two values simultaneously: the
persistent clock value, and the boot time.

Replace read_boot_clock64() with:
read_persistent_wall_and_boot_offset(wall_time, boot_offset)

Where wall_time is returned by read_persistent_clock() And boot_offset is
wall_time - boot time, which defaults to 0.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: peterz@infradead.org
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-16-pasha.tatashin@oracle.com
2018-07-20 00:02:40 +02:00
..
alarmtimer.c alarmtimer: Init nanosleep alarm timer on stack 2018-03-29 16:10:07 +02:00
clockevents.c
clocksource.c clocksource: Move inline keyword to the beginning of function declarations 2018-05-16 22:21:32 +02:00
hrtimer.c posix-timers: Fix nanosleep_copyout() for CONFIG_COMPAT_32BIT_TIME 2018-06-19 09:23:19 +02:00
itimer.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
jiffies.c
Kconfig sched/isolation: Eliminate NO_HZ_FULL_ALL 2018-02-15 15:40:37 -08:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ntp_internal.h Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
ntp.c jiffies: Introduce USER_TICK_USEC and redefine TICK_USEC 2018-04-06 09:28:50 +02:00
posix-clock.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
posix-cpu-timers.c posix-cpu-timers: Remove lockdep_assert_irqs_disabled() 2018-06-12 17:18:37 +02:00
posix-stubs.c Merge branch 'linus' into timers/2038 2018-05-19 13:55:40 +02:00
posix-timers.c Merge branch 'linus' into timers/2038 2018-05-19 13:55:40 +02:00
posix-timers.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sched_clock.c
test_udelay.c
tick-broadcast-hrtimer.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tick-broadcast.c tick/broadcast: Use for_each_cpu() specially on UP kernels 2018-05-15 22:45:54 +02:00
tick-common.c Revert "tick: Prefer a lower rating device only if it's CPU local device" 2018-07-10 22:12:47 +02:00
tick-internal.h Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
tick-oneshot.c clockevents: Fix kernel messages split across multiple lines 2018-04-17 17:18:04 +02:00
tick-sched.c Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
tick-sched.h nohz: Gather tick_sched booleans under a common flag field 2018-04-09 11:54:57 +02:00
time.c time: Make sure jiffies_to_msecs() preserves non-zero time periods 2018-06-22 17:48:36 +02:00
timeconst.bc
timeconv.c
timecounter.c
timekeeping_debug.c
timekeeping_internal.h kdb: use __ktime_get_real_seconds instead of __current_kernel_time 2018-01-25 08:40:18 -06:00
timekeeping.c timekeeping: Replace read_boot_clock64() with read_persistent_wall_and_boot_offset() 2018-07-20 00:02:40 +02:00
timekeeping.h Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
timer_list.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00
timer.c timers: Adjust a kernel-doc comment 2018-05-13 15:55:43 +02:00