[RFC][PATCH][kprobe] enabling booster on the preemptible kernel, take 2

[Masami Hiramatsu]

Hi bibo,

bibo,mao wrote:
>>> I do not know whether there exists non-freezeable and preemptive kernel
>>> thread, if there exist then this thread will not be frozen.
>>
>> In that case, freeze_processes() returns the positive value which
>> means how many processes are not frozen. If freeze_processes()
>> returns non-zero, this function aborts the garbage collection.
>>
> But from the code, return value of freeze_processes() represents how many
> processes can be frozen but are not frozen. I grep the kernel code, there
> still exists many processes which flag is PF_NOFREEZE.
> I think if current probed thread is PF_NOFREEZE, then kprobe_handler
> need skip the bootser.

OK, I see.
It seems problematic because the softirqd is PF_NOFREEZE and it
can execute most of functions...
I think we need to find a new way to solve this problem.

Thank you for your advice.

-- 
Masami HIRAMATSU
Linux Technology Center
Hitachi, Ltd., Systems Development Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com