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

[Karel Zak <kzak@redhat.com>]

On Thu, Feb 05, 2009 at 03:44:42PM +0100, Harald Hoyer wrote:
> Ingo Molnar wrote:
>> * Pavel Machek <pavel@suse.cz> wrote:
>>
>>> On Tue 2009-01-27 12:08:04, Kok, Auke wrote:
>>>> This tracer monitors regular file open() syscalls. This is a fast
>>>> and low-overhead alternative to strace, and does not allow or
>>>> require to be attached to every process.
>>>>
>>>> The tracer only logs succesfull calls, as those are the only ones we
>>>> are currently interested in, and we can determine the absolute path
>>>> of these files as we log.
>>> Maybe fanotify() should be used instead?
>>>
>>> Or maybe just plain strace? One slow boot should not really hurt...
>>
>> ptrace is out of question for good tracing because it's not a 
>> transparent probe. (ptrace monopolizes the traced task - if we use that 
>> then we break regular strace usage.)
>>
>> 	Ingo
>
> Can strace can be used on init?
>
> $ man strace
> ...
>        On Linux, exciting as it would be, tracing the init process is forbidden.
> ...
>
> Any hope getting _any_ mechanism in the kernel??

 Do you remember Linux Auditing System? That's RH's baby with hooks to
 all relevant syscalls. It would be better to fix/improve the current
 kernel mechanisms that introduce a new one.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>