Re: [PATCHv10 2.6.35-rc6-tip 9/14] trace: uprobes trace_event interface

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Aug 02, 2010 at 12:45:08PM +0900, Masami Hiramatsu wrote:
> Frederic Weisbecker wrote:
> > On Thu, Jul 29, 2010 at 02:04:14PM +0900, Masami Hiramatsu wrote:
> >> Srikar Dronamraju wrote:
> >>> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> >>> index c681fa7..16e2a8c 100644
> >>> --- a/kernel/trace/Kconfig
> >>> +++ b/kernel/trace/Kconfig
> >>> @@ -482,6 +482,22 @@ config RING_BUFFER_BENCHMARK
> >>>  
> >>>  	  If unsure, say N.
> >>>  
> >>> +config UPROBE_EVENT
> >>> +	bool "Enable uprobes-based dynamic events"
> >>> +	depends on ARCH_SUPPORTS_UPROBES
> >>> +	depends on MMU
> >>> +	select UPROBES
> >>> +	select PROBE_EVENTS
> >>> +	select TRACING
> >>> +	default n
> >>> +	help
> >>> +	  This allows the user to add tracing events on top of userspace dynamic
> >>> +	  events (similar to tracepoints) on the fly via the traceevents interface.
> >>> +	  Those events can be inserted wherever uprobes can probe, and record
> >>> +	  various registers.
> >>> +	  This option is required if you plan to use perf-probe subcommand of perf
> >>> +	  tools on user space applications.
> >>> +
> >> Possible enhancement: Moving this config right after KPROBE_EVENT, because
> >>  those two provide similar dynamic events.
> >>
> >> Thank you,
> > 
> > 
> > In fact this could be a menu "Dynamic Probes", perhaps default off, inside
> > which Kprobes and Uprobes would be default on (but depend on "Dynamic Probes").
> > 
> > So that you can quickly enable them all in one.
> 
> Hmm, I disagree with it, because both Kprobes and Uprobes provides
> APIs for modules too.


I'm not sure there is a point in maintaining a leightweight version
for out of tree code. These modules could just select kprobes/uprobes
events as well.

As you prefer, that was just a suggestion to make it more simple.



> 
> I'd like to suggest below config tree
> 
> Kenrel hacking
>   - Kprobes
>   - Uprobes
>   - Tracing
>      -- Dynamic Events
>         depends on Kprobes || Uprobes


Yep, that version looks good.