kernel_optimize_test/kernel/time
Paul E. McKenney d9b40ebd44 clocksource: Check per-CPU clock synchronization when marked unstable
[ Upstream commit 7560c02bdffb7c52d1457fa551b9e745d4b9e754 ]

Some sorts of per-CPU clock sources have a history of going out of
synchronization with each other.  However, this problem has purportedy been
solved in the past ten years.  Except that it is all too possible that the
problem has instead simply been made less likely, which might mean that
some of the occasional "Marking clocksource 'tsc' as unstable" messages
might be due to desynchronization.  How would anyone know?

Therefore apply CPU-to-CPU synchronization checking to newly unstable
clocksource that are marked with the new CLOCK_SOURCE_VERIFY_PERCPU flag.
Lists of desynchronized CPUs are printed, with the caveat that if it
is the reporting CPU that is itself desynchronized, it will appear that
all the other clocks are wrong.  Just like in real life.

Reported-by: Chris Mason <clm@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Feng Tang <feng.tang@intel.com>
Link: https://lore.kernel.org/r/20210527190124.440372-2-paulmck@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:56:01 +02:00
..
alarmtimer.c kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data() 2021-03-25 09:04:16 +01:00
clockevents.c tick: Remove outgoing CPU from broadcast masks 2019-03-23 18:26:43 +01:00
clocksource.c clocksource: Check per-CPU clock synchronization when marked unstable 2021-07-14 16:56:01 +02:00
hrtimer.c kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data() 2021-03-25 09:04:16 +01:00
itimer.c time: Prevent undefined behaviour in timespec64_to_ns() 2020-10-26 11:48:11 +01:00
jiffies.c timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
Kconfig posix-cpu-timers: Provide mechanisms to defer timer handling to task_work 2020-08-06 16:50:59 +02:00
Makefile ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
namespace.c nsproxy: support CLONE_NEWTIME with setns() 2020-07-08 11:14:22 +02:00
ntp_internal.h ntp: Audit NTP parameters adjustment 2019-04-15 18:14:01 -04:00
ntp.c ntp/y2038: Remove incorrect time_t truncation 2019-11-12 08:13:44 +01:00
posix-clock.c posix-clocks: Rename the clock_get() callback to clock_get_timespec() 2020-01-14 12:20:49 +01:00
posix-cpu-timers.c kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data() 2021-03-25 09:04:16 +01:00
posix-stubs.c posix-timers: Make clock_nanosleep() time namespace aware 2020-01-14 12:20:55 +01:00
posix-timers.c posix-timers: Preserve return value in clock_adjtime32() 2021-05-11 14:47:16 +02:00
posix-timers.h posix-clocks: Introduce clock_get_ktime() callback 2020-01-14 12:20:51 +01:00
sched_clock.c time/sched_clock: Mark sched_clock_read_begin/retry() as notrace 2020-10-26 11:34:31 +01:00
test_udelay.c time/debug: Remove license boilerplate 2018-11-23 11:51:21 +01:00
tick-broadcast-hrtimer.c tick: broadcast-hrtimer: Fix a race in bc_set_next 2019-09-27 14:45:55 +02:00
tick-broadcast.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
tick-common.c timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
tick-internal.h tick: Remove outgoing CPU from broadcast masks 2019-03-23 18:26:43 +01:00
tick-oneshot.c hrtimers/tick/clockevents: Remove sloppy license references 2018-11-23 11:51:21 +01:00
tick-sched.c tick/sched: Remove bogus boot "safety" check 2021-01-06 14:56:55 +01:00
tick-sched.h tick/sched: Update tick_sched struct documentation 2019-03-24 20:29:32 +01:00
time.c y2038: remove unused time32 interfaces 2020-02-21 11:22:15 -08:00
timeconst.bc time: Add SPDX license identifiers 2018-11-23 11:51:20 +01:00
timeconv.c time: Add SPDX license identifiers 2018-11-23 11:51:20 +01:00
timecounter.c time: Remove license boilerplate 2018-11-23 11:51:21 +01:00
timekeeping_debug.c timekeeping/debug: No need to check return value of debugfs_create functions 2019-01-29 20:08:41 +01:00
timekeeping_internal.h timekeeping/vsyscall: Provide vdso_update_begin/end() 2020-08-06 10:57:30 +02:00
timekeeping.c These are the locking updates for v5.10: 2020-10-12 13:06:20 -07:00
timekeeping.h timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
timer_list.c timer_list: Guard procfs specific code 2019-06-23 00:08:52 +02:00
timer.c timers: Remove unused inline funtion debug_timer_free() 2020-10-26 11:39:21 +01:00
vsyscall.c timekeeping/vsyscall: Provide vdso_update_begin/end() 2020-08-06 10:57:30 +02:00