From: Fenghua Yu <fenghua...@intel.com> During reboot, in the middle of disabling IO APIC, the scheduler may be triggered by per cpu timer to do load blance. But since the kernel is already in the process of shutting down and can not execute scheduler's load balance at this point, it triggers invalid TSS exception and hangs during reboot.
This happens on some boards (e.g. AsRock ZT87 Extreme4 BIOS 2.70) in 32-bit kernel reported in Bugzilla 76661 at https://bugzilla.kernel.org/show_bug.cgi?id=76661 To fix the issue, we disable local irq including per cpu timer before disabling IO APIC. By doing this, the scheduler will not disturb disable_IO_APIC(). Signed-off-by: Fenghua Yu <fenghua...@intel.com> Tested-by: berndku...@hotmail.com --- arch/x86/kernel/reboot.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 52b1157..16111c6 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -574,6 +574,15 @@ static void native_machine_emergency_restart(void) void native_machine_shutdown(void) { /* Stop the cpus and apics */ + +#ifdef CONFIG_SMP + /* + * Disable the local irq to not receive the per-cpu timer interrupt + * which may trigger scheduler's load balance. + */ + local_irq_disable(); +#endif + #ifdef CONFIG_X86_IO_APIC /* * Disabling IO APIC before local APIC is a workaround for @@ -591,11 +600,8 @@ void native_machine_shutdown(void) #ifdef CONFIG_SMP /* - * Stop all of the others. Also disable the local irq to - * not receive the per-cpu timer interrupt which may trigger - * scheduler's load balance. + * Stop all of the others. */ - local_irq_disable(); stop_other_cpus(); #endif -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
