Re: [PATCH] sysrq show-all-cpus

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

Rik van Riel wrote:
> SysRQ-P is not always useful on SMP systems, since it usually ends up showing the
> backtrace of a CPU that is doing just fine, instead of the backtrace of the CPU
> that is having problems.
> 
> This patch adds SysRQ show-all-cpus(L), which shows the backtrace of every active
> CPU in the system.  It skips idle CPUs because some SMP systems are just too large
> and we already know what the backtrace of the idle task looks like.
>  
> Signed-off-by: Rik van Riel <riel@redhat.com>
> 
> diff -up linux-2.6.25-rc3-mm1/Documentation/sysrq.txt.multicpu linux-2.6.25-rc3-mm1/Documentation/sysrq.txt
> --- linux-2.6.25-rc3-mm1/Documentation/sysrq.txt.multicpu	2008-03-10 13:49:18.000000000 -0400
> +++ linux-2.6.25-rc3-mm1/Documentation/sysrq.txt	2008-03-10 13:51:09.000000000 -0400
> @@ -85,6 +85,8 @@ On all -  write a character to /proc/sys
>  'k'     - Secure Access Key (SAK) Kills all programs on the current virtual
>            console. NOTE: See important comments below in SAK section.
>  
> +'l'     - Shows a stack backtrace for all active CPUs.
> +
>  'm'     - Will dump current memory info to your console.
>  
>  'n'	- Used to make RT tasks nice-able

Yep, thanks.
A diffstat is also appreciated (in the future).

-- 
~Randy