Subject: Re: [Kgdb-bugreport] 2.6.23-rc3-mm1: kgdb build failure on powerpc

From: Pete/Piet Delaney <[email-masked]>
Date: Wed, 29 Aug 2007 17:05:25 -0700

Pete/Piet Delaney wrote:
> Jason Wessel wrote:
>> Andrew Morton wrote:
>>> On Wed, 22 Aug 2007 17:44:12 -0500
>>> Jason Wessel <[email-masked]> wrote:
>>>
>>>  
>>>> +    while (!atomic_read(&debugger_active));
>>>>     
>>> eek.  We're in the process of hunting down and eliminating exactly this
>>> construct.  There have been cases where the compiler cached the
>>> atomic_read() result in a register, turning the above into an infinite
>>> loop.
>>>
>>> Plus we should never add power-burners like that into the kernel
>>> anyway. That loop should have a cpu_relax() in it.  Which will also
>>> fix the
>>> compiler problem described above.
>>>
>>>   
>> Agreed, and fixed with a cpu_relax.
> 
>>> Thirdly, please always add a newline when coding statements like that:
>>>
>>>     while (expr())
>>>         ;
>>>   
>> The other instances I found of the same problem in the kgdb core are
>> fixed too.
> 
>> I merged all the changes into the for_mm branch in the kgdb git tree.
> 
> Where is the kgdb git tree?

Trying:

git clone
http://master.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb.git

- -piet

> 
> -piet
> 
>> Thanks,
>> Jason.
>> -
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to [email-masked]
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at  http://www.tux.org/lkml/
> 
> 
- -
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email-masked]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/