ptrace and kernel threads

[Mulyadi Santosa]

On Fri, Feb 22, 2013 at 4:38 PM, Kevin Wilson <wkevils at gmail.com> wrote:
> Question: what is the reason that kernel threads cannot be traced while
> userspace threads can be traced ?

Subjectively, I think that's because most kernel threads play
important roles in kernel's works. So tracing them might either slows
them or interfere them somehow. Especially since it's from user space,
kernel can be interrupted badly.

I think that's why ftrace introduced. Because ftrace itself is inside
kernel space, so it can be trusted.

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com