Re: [PATCH] panic: keep blinking in spite of long spin timer mode

[Randy Dunlap <randy.dunlap@oracle.com>]

On Fri, 28 May 2010 06:56:45 +0900 TAMUKI Shoichi wrote:

> To keep panic_timeout accuracy when running under a hypervisor, the
> current implementation only spins on long time (1 second) calls to
> mdelay.  That brings a good effect, but we must give up blinking even
> if we have a panic_blink.
> 
> This patch keeps blinking in spite of long spin timer mode.
> 
> We now have new kernel parameter (panic_longspin) to enable long spin
> timer mode when kernel panics.  This is to be used when running under
> a hypervisor (default is disable).
> 
> Signed-off-by: TAMUKI Shoichi <tamuki@linet.gr.jp>
> ---
>  Documentation/kernel-parameters.txt |    7 +-
>  arch/arm/mach-s3c2440/mach-gta02.c  |   17 +----
>  drivers/input/serio/i8042.c         |   25 +-------
>  include/linux/kernel.h              |    2 
>  kernel/panic.c                      |   81 +++++++++++++++++---------
>  5 files changed, 70 insertions(+), 62 deletions(-)
> 
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index fc89cac..7709450 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -918,9 +918,6 @@ and is between 256 and 4096 characters. It is defined in the file
>  			     controller
>  	i8042.nopnp	[HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
>  			     controllers
> -	i8042.panicblink=
> -			[HW] Frequency with which keyboard LEDs should blink
> -			     when kernel panics (default is 0.5 sec)
>  	i8042.reset	[HW] Reset the controller during init and cleanup
>  	i8042.unlock	[HW] Unlock (ignore) the keylock
>  
> @@ -1870,6 +1867,10 @@ and is between 256 and 4096 characters. It is defined in the file
>  
>  	panic=		[KNL] Kernel behaviour on panic
>  			Format: <timeout>
> +	panic_longspin	[KNL] Enable long spin timer mode when kernel panics.
> +			      This is to be used when running under a hyper-
> +			      visor (default is disable)
> +	panicblink=	[KNL] The speed of panic blink (default is 12 wpm)

What is "wpm"?  In typing, it's words per minute.
Is it "winks per minute" here?  If not, what?


>  	parkbd.port=	[HW] Parallel port number the keyboard adapter is
>  			connected to, default is 0.


---
~Randy
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