Re: Help required on rda [FRV]

[Vinu Dev <vinudev at gmail dot com>]

Dear Jimb,
  Sorry for my late reply,as per ur advice i checked for  ptrace
traffic during those 4-5 seconds,It looks like large quantity of
PTRACE_PEEKTEXT-1 is  issued to target program from
rda,i tried recording those ptrace traffic,here is the sample of it 
************************************************************************
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
PTRACE_PEEKTEXT-1 0x02200690 in 266, 0x2a881000
PTRACE_POKETEXT 0x02200690 in 266, 0xffffffffc0700001
<ptrace (PTRACE_CONT, 266, 0, 0)>
<check_child_state: 266 got 'T' - 5 at 0x02200690>
<select_pending_event: pid 266 'T' 5>
wait returned 'T' (5) for 266.
PTRACE_GETFDPIC pid=266 offset=0 val=21ffcb0
PTRACE_GETFDPIC pid=266 offset=1 val=21ffca0
PTRACE_POKETEXT 0x02200690 in 266, 0x2a881000
PTRACE_PEEKTEXT-1 0x02204fe8 in 266, 0x00025068
PTRACE_PEEKTEXT-1 0x00025068 in 266, 0x021ffcb0
PTRACE_PEEKTEXT-1 0x0002506c in 266, 0x02204fe0
PTRACE_PEEKTEXT-1 0x00025070 in 266, 0x0001ee24
PTRACE_PEEKTEXT-1 0x00025074 in 266, 0x02204ebc
PTRACE_PEEKTEXT-1 0x00025078 in 266, 0x00025548
PTRACE_PEEKTEXT-1 0x0002507c in 266, 0x00000000
PTRACE_PEEKTEXT-1 0x00025548 in 266, 0x000257a0
PTRACE_PEEKTEXT-1 0x0002554c in 266, 0x0003cb60
PTRACE_PEEKTEXT-1 0x00025550 in 266, 0x00025530
PTRACE_PEEKTEXT-1 0x00025554 in 266, 0x0003c478
PTRACE_PEEKTEXT-1 0x00025558 in 266, 0x000257c0
PTRACE_PEEKTEXT-1 0x0002555c in 266, 0x00025068
PTRACE_PEEKTEXT-1 0x000257a0 in 266, 0x00000001
PTRACE_PEEKTEXT-1 0x000257a4 in 266, 0x00028000
PTRACE_PEEKTEXT-1 0x000257a8 in 266, 0x00000000
PTRACE_PEEKTEXT-1 0x000257ac in 266, 0x00056d20
PTRACE_PEEKTEXT-1 0x00025530 in 266, 0x2f6c6962
.
.
.
.
PTRACE_PEEKTEXT-1 0x000148dc in 266, 0xffffffff80880000
< -- failed, thread_agent = 0x00000000>
< -- failed, thread_agent = 0x00000000>
PTRACE_PEEKTEXT-1 0x0003783c in 266, 0x322e332e
PTRACE_PEEKTEXT-1 0x00037840 in 266, 0x332d6672
PTRACE_PEEKTEXT-1 0x00037844 in 266, 0x762d3034
PTRACE_PEEKTEXT-1 0x00037848 in 266, 0x30383230
PTRACE_PEEKTEXT-1 0x0003784c in 266, 0x2d330000
< -- failed, thread_agent = 0x0221e3f8>
PTRACE_PEEKTEXT-1 0x0003783c in 266, 0x322e332e
PTRACE_PEEKTEXT-1 0x00037840 in 266, 0x332d6672
PTRACE_PEEKTEXT-1 0x00037844 in 266, 0x762d3034
PTRACE_PEEKTEXT-1 0x00037848 in 266, 0x30383230
PTRACE_PEEKTEXT-1 0x0003784c in 266, 0x2d330000
< -- failed, thread_agent = 0x0221e3f8>
PTRACE_PEEKTEXT-1 0x0003783c in 266, 0x322e332e
************************************************************************************************
PTRACE_PEEKTEXT-1 is used by rda to get information from target
 program.  It read 4byte(unsigned long) data in each time.Now i
suspect this is reason why we are having the delay in debugging
thread.

Can u pls help me as 
1) Who issues these PTRACE_PEEKTEXT-1.
2) What cause this (why a large quantity of PTRACE_PEEKTEXT-1 issued to
   target program from rda)

Regards
Vinu





On 4/28/05, Vinu Dev <vinudev@gmail.com> wrote:
> ---------- Forwarded message ----------
> From: Jim Blandy <jimb@redhat.com>
> Date: 27 Apr 2005 03:45:03 -0500
> Subject: Re: Help required on rda [FRV]
> To: Vinu Dev <vinudev@gmail.com>
> Cc: rda@sources.redhat.com
> 
> Vinu Dev <vinudev@gmail.com> writes:
> > Dear JimB,
> >  Thanks for your reply,iam using LinuxThreads,its my requirement to
> > use linuxthreads.
> >    Even i was surprised by the delay factor,is there any other way to
> > measure the thread creation time more precise than using
> > gettimeofday() system call,if u could advice me on this,i would be
> > very much thankfull to you.
> >   The delay is around 4-5 secs for each thread creation via rda.
> >  Is there any article or technical documents or could u guide me to
> > know  the cause for this delay?
> 
> 4-5 seconds sounds about right.  If I remember correctly, it's due to
> libthread_db's need to read huge amounts of memory from the program
> being debugged each time it stops.
> 
> Take a look at rda/unix/linux-target.c:linux_process_rcmd.  That's the
> function that gets called when you give GDB the "monitor" command.  So
> 
>         (gdb) monitor 1
> 
> (I think) should turn on debugging output in RDA, and
> 
>         (gdb) monitor 0
> 
> should turn it off.  If you'd like to be able to do other things to
> RDA, you can add more stuff to linux_process_rcmd.
> 
> In any case, after 'monitor 1', RDA will print messages describing
> all the ptrace calls it makes.  If I'm right, you'll see a *lot* of
> ptrace traffic during those 4-5 seconds.
> 
> You might also try changing the initialization of thread_db_noisy to
> 1, to see more of what thread_db.c is doing.
> 
> Good luck!
> 
> --
> Regards,
> Vinay
> 


-- 
Regards,
Vinay