Re: [RFC PATCH -tip 0/9]ftrace, kprobes: Ftrace-based kprobe optimization

[Masami Hiramatsu]

(2012/05/30 7:45), Steven Rostedt wrote:
> On Tue, 2012-05-29 at 21:48 +0900, Masami Hiramatsu wrote:
> 
>> Also, this makes all __kprobes functions "notrace", because
>> some of those functions are considered as to be called from
>> kprobes handler which is called from function tracer.
>> I think that is another discussion point. Perhaps, we need
>> to introduce another tag which means "don't put kprobe on
>> this function" instead of __kprobes and apply that.
> 
> Actually, instead, we can force kprobes to have all "__kprobes"
> functions added to its 'notrace' ftrace_ops. This will just keep kprobes
> from function tracing these, as I find myself tracing functions marked
> by kprobes quite a bit.

Hmm, I'm not so sure how the notrace and filter works.
What happens if I set a foo function-entry on filter
and keep notrace empty?
 - only foo's nop is replaced with call?
 - or all functions including foo is traced?

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
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