dtrace discuss - May 2007 - printf type functionality from kernel sdt probes

Is there any way to get printf type functionality inside the kernel from dtrace
probes. Basically I want to dump progress through flow in my device driver.
Something like:

DTRACE_PRINTF("Inside chip reset, mailboxes %x %x %x %x %x %x %x %x",
mb1, mb2, .....);
 ...
 ...
DTRACE_PRINTF("reset failed: reason %s", failure_reasons[err]);

I may have several such probes and they may change very frequently during the
development. The dtrace script to enable these probes and dump values can be
very simple and will just enable all the probes inside my device driver.

Thanks
Sumit
--
This message posted from opensolaris.org

Sumit Gupta writes:
> Is there any way to get printf type functionality inside the kernel from
dtrace probes. Basically I want to dump progress through flow in my device
driver. Something like:
> 
> DTRACE_PRINTF("Inside chip reset, mailboxes %x %x %x %x %x %x %x
%x", mb1, mb2, .....);
>  ...
>  ...
> DTRACE_PRINTF("reset failed: reason %s", failure_reasons[err]);
> 
> I may have several such probes and they may change very frequently during
the development. The dtrace script to enable these probes and dump values can be
very simple and will just enable all the probes inside my device driver.
dtrace != printf

You could look into sdt probes, which look like this:

	DTRACE_PROBE2(chip__reset, mailbox_t *, mb1, mailbox_t *, mb2);

... but it sounds like what you really want is either cmn_err or just
plain old printf.  Those functions are still there, still work fine,
and aren''t going away.

I''d suggest that if you''re not planning to embrace the dtrace
way of
doing things (separating out instrumentation from presentation), then
you might be barking up the wrong tree.

-- 
James Carlson, Solaris Networking              <james.d.carlson at
sun.com>
Sun Microsystems / 1 Network Drive         71.232W   Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757   42.496N   Fax +1 781 442 1677

Sumit Gupta wrote:
> Is there any way to get printf type functionality inside the kernel from
dtrace probes. Basically I want to dump progress through flow in my device
driver. Something like:
> 
> DTRACE_PRINTF("Inside chip reset, mailboxes %x %x %x %x %x %x %x
%x", mb1, mb2, .....);
>  ...
>  ...
> DTRACE_PRINTF("reset failed: reason %s", failure_reasons[err]);
> 
> I may have several such probes and they may change very frequently during
the development. The dtrace script to enable these probes and dump values can be
very simple and will just enable all the probes inside my device driver.
IMO, you need to do the recording of data in your probes and the 
printf''ing in your consumer, ie the DTrace script.

HTH
Michael
-- 
Michael Schuster
Recursion, n.: see ''Recursion''

Sure sounds like to me you''re real question is: "How do I record
my own
data." and the answer is "USDT probes", which is documented in
the
manual in chapter .... just a minute ....  34, Statically Defined 
Tracing for User Applications.

Chip

Sumit Gupta wrote:
> Is there any way to get printf type functionality inside the kernel from
dtrace probes. Basically I want to dump progress through flow in my device
driver. Something like:
>
> DTRACE_PRINTF("Inside chip reset, mailboxes %x %x %x %x %x %x %x
%x", mb1, mb2, .....);
>  ...
>  ...
> DTRACE_PRINTF("reset failed: reason %s", failure_reasons[err]);
>
> I may have several such probes and they may change very frequently during
the development. The dtrace script to enable these probes and dump values can be
very simple and will just enable all the probes inside my device driver.
>
> Thanks
> Sumit
> --
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>