ftrace introduces instability into kernel 2.6.27(-rc2,-rc3)

[Jeremy Fitzhardinge]

Benjamin Herrenschmidt wrote:
>> Ok, there are two cases where it's ok :
>>
>> 1 - in stop_machine, considering we are not touching code executed in
>> NMI handlers.
>> 2 - when using my replace_instruction_safe() which uses a temporary
>> breakpoint when doing the instruction replacement.
>>
>> In those cases you could use text_poke_early().
>>     
>
> Note that vmap/vunmap will be very slow.
>   

Don't we have Nick's speedups now?

    J