dtrace discuss - Mar 2006 - Dtrace not working for processes running after acouple of hours

Hi, all,

Jarod Jenson was able to help me to determine that the process is not
doing much when it happens. Guess that we can call an end to it.

Thanks for all the replies,
Jianbing

-----Original Message-----
From: dtrace-discuss-bounces at opensolaris.org
[mailto:dtrace-discuss-bounces at opensolaris.org] On Behalf Of
jianbing.chen at exgate.tek.com
Sent: Wednesday, March 01, 2006 8:08 PM
To: cbennett at laurustech.com
Cc: dtrace-discuss at opensolaris.org
Subject: RE: [dtrace-discuss] Dtrace not working for processes running
after acouple of hours

Chip,

It''s in c++ and with "gcc -g -O2". Still, it''s hard
to explain the
non-deterministic behavior with the only difference on the lifespan of
the process.

Thanks for helping out,
Jianbing



-----Original Message-----
From: Chip Bennett [mailto:cbennett at laurustech.com]
Sent: Wed 3/1/2006 6:57 PM
To: Chen, Jianbing
Cc: dtrace-discuss at opensolaris.org
Subject: Re: [dtrace-discuss] Dtrace not working for processes running
after a couple of hours
 
Just for grins I wrote a small C program that called one function, and 
then ran your script against it.  I was seeing the function entry until 
I compiled using "gcc -O3", which will take functions and try to 
"inline" them.  This is going to cause the function to not form a
proper

stack trace.  The interesting part is that my function name was still 
available to match the probe, but there was no action output.

Could something like that be happening to you?  What language is your 
program in?

Chip

jianbing.chen at exgate.tek.com wrote:
>Pid$1::func, which is some user library function.
>
>BTW, the function call that I''m tracing is getting called close to
100
>times per second.
>
>The interesting part is that for a process with less than 1 hour age,
it
>works every time.
>
>Thanks,
>Jianbing
> 
>
>-----Original Message-----
>From: Nicolas Williams [mailto:Nicolas.Williams at sun.com] 
>Sent: Wednesday, March 01, 2006 5:51 PM
>To: Chen, Jianbing
>Cc: dtrace-discuss at opensolaris.org
>Subject: Re: [dtrace-discuss] Dtrace not working for processes running
>after a couple of hours
>
>On Wed, Mar 01, 2006 at 05:37:35PM -0600, jianbing.chen at exgate.tek.com
>wrote:
>  
>
>>Hi, all,
>> 
>>I''m a newbie on dtrace and the problem I am having is: 
>>    For processes which have been running for more than a couple of 
>>hours, dtrace doesn''t seem to be able to trace(I waited for at
least
>>one hour and didn''t see anything happening). However, it works
every
>>time for a relatively new process.
>>    
>>
>
>What probes are you tracing?  I''ve seen processes run for hours
without
>making a single system call, for example, and it''s even possible
that a
>process could run for hours without taking any page faults or receiving
>signals.  Attaching to it with a debugger and single-stepping it may
>help.  Watching it go on and off cpu with dtrace may help show that
it''s
>executing something.
>_______________________________________________
>dtrace-discuss mailing list
>dtrace-discuss at opensolaris.org
>  
>

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