Re: [PATCH] tracer for sys_open() - sreadahead

["Frédéric Weisbecker" <fweisbec@gmail.com>]

2009/1/29 Frédéric Weisbecker <fweisbec@gmail.com>:
> 2009/1/29 Ingo Molnar <mingo@elte.hu>:
>>>
>>> Several people talked me about utrace and gave some examples about it in
>>> this discussion. The Api is very convenient to fetch syscall numbers,
>>> arguments and return values. And the hooks are done in the generic core
>>> code, so it is arch independent.
>>>
>>> The only drawback I can see is that it is not yet merged upstream, in
>>> need of in-kernel users. If it only depends on this condition, we could
>>> be these users...
>>>
>>> What do you think?
>>
>> sure - how do the minimal bits/callbacks look like which enable syscall
>> tracing?
>>
>>        Ingo
>
>
> There is a very straightforward example provided by Ananth in there:
> http://lkml.org/lkml/2009/1/28/59
>

One other drawback may be the fact that utrace will be traced by the
function tracers... adding some junk on their traces.
But I guess this is just a matter of some patches to make it not traced.

BTW, there is an interesting proof of concept there:
http://lkml.org/lkml/2009/1/27/294