Re: [PATCH] x86: call machine_shutdown and stop all CPUs in native_machine_halt

From: Neil Horman
Date: Mon Oct 20 2008 - 10:40:12 EST


On Mon, Oct 20, 2008 at 02:13:07PM +0200, Ivan Vecera wrote:
> Function machine_halt (resp. native_machine_halt) is empty for x86
> architectures. When command 'halt -f' is invoked, the message
> "System halted." is displayed but this is not really true because
> all CPUs are still running.
> There are also similar inconsistencies for other arches (some uses
> power-off for halt or forever-loop with IRQs enabled/disabled).
> IMO there should be used the same approach for all architectures
> OR what does the message "System halted" really mean?
>
> Signed-off-by: Ivan Vecera <ivecera@xxxxxxxxxx>
> ---
> arch/x86/kernel/reboot.c | 8 ++++++++
> 1 files changed, 8 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
> index f4c93f1..15ad949 100644
> --- a/arch/x86/kernel/reboot.c
> +++ b/arch/x86/kernel/reboot.c
> @@ -465,6 +465,14 @@ static void native_machine_restart(char *__unused)
>
> static void native_machine_halt(void)
> {
> + /* stop other cpus and apics */
> + machine_shutdown();
> +
> + /* stop this cpu */
> + local_irq_disable();
> + if (hlt_works(smp_processor_id()))
> + for (;;) halt();
> + for (;;);
> }
>
> static void native_machine_power_off(void)
> --
> 1.5.6.3
>

Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>

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*Neil Horman
*Senior Software Engineer
*Red Hat, Inc.
*nhorman@xxxxxxxxxx
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*http://pgp.mit.edu
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