linux/kernel/time
Dexuan Cui 5596fe3449 tick/broadcast: Use for_each_cpu() specially on UP kernels
for_each_cpu() unintuitively reports CPU0 as set independent of the actual
cpumask content on UP kernels. This causes an unexpected PIT interrupt
storm on a UP kernel running in an SMP virtual machine on Hyper-V, and as
a result, the virtual machine can suffer from a strange random delay of 1~20
minutes during boot-up, and sometimes it can hang forever.

Protect if by checking whether the cpumask is empty before entering the
for_each_cpu() loop.

[ tglx: Use !IS_ENABLED(CONFIG_SMP) instead of #ifdeffery ]

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poulson <jopoulso@microsoft.com>
Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: stable@vger.kernel.org
Cc: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Jork Loeser <Jork.Loeser@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: https://lkml.kernel.org/r/KL1P15301MB000678289FE55BA365B3279ABF990@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
Link: https://lkml.kernel.org/r/KL1P15301MB0006FA63BC22BEB64902EAA0BF930@KL1P15301MB0006.APCP153.PROD.OUTLOOK.COM
2018-05-15 22:45:54 +02:00
..
alarmtimer.c alarmtimer: Init nanosleep alarm timer on stack 2018-03-29 16:10:07 +02:00
clockevents.c clockevents: Retry programming min delta up to 10 times 2017-10-19 16:29:15 +02:00
clocksource.c clocksource: Rework stale comment 2018-05-02 16:10:41 +02:00
hrtimer.c Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +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 jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC 2017-03-07 11:03:28 +01:00
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: Ensure set_process_cpu_timer is always evaluated 2018-04-19 12:54:57 +02:00
posix-stubs.c Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
posix-timers.c Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +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 timers, sched_clock: Update timeout for clock wrap 2017-03-23 12:30:27 -07:00
test_udelay.c time: Avoid timespec in udelay_test 2016-06-20 12:47:26 -07:00
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: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +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 y2038: Introduce struct __kernel_old_timeval 2018-03-19 15:23:03 +01:00
timeconst.bc time: Introduce jiffies64_to_nsecs() 2017-02-01 09:13:45 +01:00
timeconv.c time: Add time64_to_tm() 2016-06-20 12:47:15 -07:00
timecounter.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timekeeping_debug.c PM / timekeeping: Print debug messages when requested 2017-07-23 00:03:43 +02:00
timekeeping_internal.h kdb: use __ktime_get_real_seconds instead of __current_kernel_time 2018-01-25 08:40:18 -06:00
timekeeping.c Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
timekeeping.h Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
timer_list.c timer/debug: Change /proc/timer_list from 0444 to 0400 2017-11-13 16:04:06 +01:00
timer.c timers: Forward timer base before migrating timers 2018-02-28 23:34:33 +01:00