Re: [RFC 3/4] perf, ftrace: Add new perf ioctl for function tracefilter

[Frederic Weisbecker]

On Mon, Jul 11, 2011 at 03:22:55PM +0200, Jiri Olsa wrote:
> As the amount of kernel functions obtained by the ftrace:function tracepoint
> is quite big, it's desirable to be able to set the filter on the ftrace
> level.
> 
> Added PERF_EVENT_IOC_SET_FTRACE ioctl to be able to specify function filter
> for perf event. The interface is the same as for the set_ftrace_filter file.
> 
> Also the same string parser is used as for the set_ftrace_filter file.

I'm not sure I understand why an ioctl is needed for that.
Why not using the ftrace filter?

The first idea was to do something like this:

	ip == func1 || ip == func2 || ....

But that makes a too long expression. So I thought we
could bring support for the "+" operator and have expressions
like:

	ip == func1 + func2 + func3 + ....

	ip == !func1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/