dtrace discuss - Jan 2007 - proc:::create fires too many times

Hi.

    I''m missing something really obvious or...


# dtrace -n proc:::create''/zonename ==
"test"/{@[execname,pid,ppid]=count();}'' -n
tick-5s''{printa(@);}''
[...]
  wp-ldapreplika-t                                      16332    16326          
279


It looks like probe proc:::create fired 279 times for pid 16332 being created
from ppid 16326.


System is Generic_118833-33 sun4v
 
 
This message posted from opensolaris.org

Looks like pid and ppid are set differently in a contex of proc:::create

# dtrace -n proc:::create''/zonename ==
"test"/{@[execname,args[0]->pr_pid,pid,args[0]->pr_ppid,ppid]=count();}''
-n tick-5s''{printa(@);}''
[...]
  wp-ldapreplika-t                                       4815     4417     4417 
4400                1
  wp-ldapreplika-t                                       4935     4417     4417 
4400                1
  wp-ldapreplika-t                                       4938     4417     4417 
4400                1
  wp-ldapreplika-t                                       4806     4417     4417 
4400                1
  wp-ldapreplika-t                                       4801     4417     4417 
4400                1


so (psinfo_t *)->pr_pid is not the same as pid variable, and actually pid
variable is equal to (psinfo_t *)->pr_pprid and I guess ppid is actualy
(psinfo_t *)->pr_ppid of ppid.

So it would explain a little bit why I saw proc::create firing so many time for
the same pid - it wasn''t pid of created process.
 
 
This message posted from opensolaris.org

Hey Robert,

The proc:::create probe fires in the context of the parent of the newly
created process so the pid and ppid you''ll see are those of the parent.
If you think thhe documentation could be clearer on this point, feel free
to file a bug in doc/dtrace.

Adam

On Mon, Jan 29, 2007 at 06:41:13AM -0800, Robert Milkowski
wrote:
> Looks like pid and ppid are set differently in a contex of proc:::create
> 
> # dtrace -n proc:::create''/zonename ==
"test"/{@[execname,args[0]->pr_pid,pid,args[0]->pr_ppid,ppid]=count();}''
-n tick-5s''{printa(@);}''
> [...]
>   wp-ldapreplika-t                                       4815     4417    
4417     4400                1
>   wp-ldapreplika-t                                       4935     4417    
4417     4400                1
>   wp-ldapreplika-t                                       4938     4417    
4417     4400                1
>   wp-ldapreplika-t                                       4806     4417    
4417     4400                1
>   wp-ldapreplika-t                                       4801     4417    
4417     4400                1
> 
> 
> so (psinfo_t *)->pr_pid is not the same as pid variable, and actually
pid variable is equal to (psinfo_t *)->pr_pprid and I guess ppid is actualy
(psinfo_t *)->pr_ppid of ppid.
> 
> So it would explain a little bit why I saw proc::create firing so many time
for the same pid - it wasn''t pid of created process.
>  
>  
> This message posted from opensolaris.org
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Solaris Kernel Development       http://blogs.sun.com/ahl

Yep, I figured it out. Thanks anyway.
 
 
This message posted from opensolaris.org