android_kernel_oneplus_msm8998/arch
Stephen Boyd 78c34e6ea3 ARM: smp: Fix hrtimer_interrupt race with sys_reboot
There are high chances for hrtimer_interrupt() interrupt on
one of the core and other core executing sys_reboot simultaneously.
In such a situation we could see ipi_cpu_stop() marking a cpu
as 'offline' but hrtimer_wakeup() can schedule a task on
offline core, resulting BUG_ON in smp_send_reschedule().
In fact that the CPU is not really offline but ipi_cpu_stop()
is marking it as offline.
CPU0                      CPU1				CPU2
sys_reboot()
 kernel_restart()
  machine_restart()
   machine_shutdown()
    smp_send_stop()					...
    ...                   ipi_cpu_stop()		hrtimer_interrupt()
                           set_cpu_online(1, false)	 __run_hrtimer()
                            local_irq_disable()		  hrtimer_wakeup()
                             while(1)			   try_to_wake_up()
							    ttwu_do_wakeup()
							     check_preempt_curr()
							      smp_send_reschedule()
							       BUG_ON(cpu_is_offline(1));

This is easily reproducible in device continuous reboot testing.
Since the CPU is not really offline and hasn't gone through the
proper steps to be marked as such, let's mark the CPU as inactive.

Change-Id: Ia1daea407220578d4212ef6c65c4be837ca370fd
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-03-25 16:02:57 -07:00
..
alpha
arc
arm ARM: smp: Fix hrtimer_interrupt race with sys_reboot 2016-03-25 16:02:57 -07:00
arm64 defconfig: Enable SPS BAM and USB BAM driver on msmcobalt 2016-03-23 21:30:45 -07:00
avr32
blackfin
c6x
cris
frv
h8300
hexagon
ia64
m32r Merge remote-tracking branch 'lsk-44/linux-linaro-lsk-v4.4' into 44rc2 2016-03-23 20:51:00 -07:00
m68k
metag
microblaze Revert "scatterlist: use sg_phys()" 2016-03-22 11:15:33 -07:00
mips
mn10300
nios2
openrisc
parisc Merge remote-tracking branch 'lsk-44/linux-linaro-lsk-v4.4' into 44rc2 2016-03-23 20:51:00 -07:00
powerpc
s390
score
sh
sparc
tile
um UM: x86_64: add defconfig file for UML on x86_64 2016-03-23 21:16:30 -07:00
unicore32
x86 Merge remote-tracking branch 'lsk-44/linux-linaro-lsk-v4.4' into 44rc2 2016-03-23 20:51:00 -07:00
xtensa
.gitignore
Kconfig