[Starpu-devel] Starpu vector_scal example execution error on 32-bit linux system

[ASD D <ajitsdeshpande@gmail.com>]

Hello ,

     I managed to resolve my earlier problem of getting Segmentation fault while executing vector_Scal example, which I had built on a Linux system. Since I was trying to build on a 64 bit Linux system,  I gave this CFLAGS=-m32 , and indeed it resolved the error and executed the vector_scal example fine with correct output.

But Just FYI – I am pasting a log of the execution on this 64 bit Linxu system, below where I see a strange error/warning below highlighted in RED, which seems like a corruption of some memory and subsequent print of a Backtrace. (Sorry for posting longish log messages within email). I m tryingto use it with moviSim openCL.

AFTER: First element is 3.140000

AFTER: Last element is 6430.720215               These are correct output values for vector_scal

 

Waiting for threads to stop...

*** glibc detected *** /home/deshpandea/moviSimStarPU/trunk/examples/basic_examples/.libs/lt-vector_scal: double free or corruption (!prev): 0x09691e00 ***

======= Backtrace: =========

/lib32/libc.so.6(+0x6b511)[0xf71e6511]

/lib32/libc.so.6(+0x6ce1b)[0xf71e7e1b]

/lib32/libc.so.6(cfree+0x6d)[0xf71eaf8d]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZN9__gnu_cxx13new_allocatorIiE10deallocate                                                                                                                                        EPij+0x11)[0xf76aa8e1]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZNSt11_Deque_baseIiSaIiEE18_M_deallocate_n                                                                                                                                        odeEPi+0x2c)[0xf76aa910]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZNSt11_Deque_baseIiSaIiEE16_M_destroy_node                                                                                                                                        sEPPiS3_+0x22)[0xf76aa934]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZNSt11_Deque_baseIiSaIiEED2Ev+0x31)[0xf76a                                                                                                                                        ace9]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZNSt5dequeIiSaIiEED1Ev+0x66)[0xf76aae86]

/home/deshpandea/moviSimStarPU/trunk/moviSim/libOpenCL.so(_ZNSt5stackIiSt5dequeIiSaIiEEED1Ev+0x11)[0x                                                                                                                                        f76aae9d]

/home/deshpandea/moviSimStarPU/trunk/moviSim/moviLibs/Linux32/shavesDll.so(+0x18c906)[0xe0600906]

/lib32/libc.so.6(+0x2f9ef)[0xf71aa9ef]

/lib32/libc.so.6(+0x2fa4f)[0xf71aaa4f]

/lib32/libc.so.6(__libc_start_main+0xef)[0xf7191e3f]

/home/deshpandea/moviSimStarPU/trunk/examples/basic_examples/.libs/lt-vector_scal[0x8048a61]

======= Memory map: ========

08048000-0804a000 r-xp 00000000 08:01 2494010                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/examples/basic_examples/.libs/lt-vector_scal

0804a000-0804b000 r--p 00001000 08:01 2494010                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/examples/basic_examples/.libs/lt-vector_scal

0804b000-08052000 rw-p 00002000 08:01 2494010                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/examples/basic_examples/.libs/lt-vector_scal

0958c000-09764000 rw-p 00000000 00:00 0                                  [heap]

ddc3e000-ddc6e000 r-xp 00000000 08:01 2101423                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/timersDll.so

ddc6e000-ddc6f000 rw-p 00030000 08:01 2101423                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/timersDll.so

ddc6f000-e0258000 rw-p 00000000 00:00 0

e0258000-e046a000 r-xp 00000000 08:01 2101424                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/leonDll.so

e046a000-e046c000 rw-p 00211000 08:01 2101424                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/leonDll.so

e046c000-e0474000 rw-p 00000000 00:00 0

e0474000-e0705000 r-xp 00000000 08:01 2101422                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/shavesDll.so

e0705000-e0709000 rw-p 00290000 08:01 2101422                            /home/deshpandea/moviSimStar                                                                                                                                        PU/trunk/moviSim/moviLibs/Linux32/shavesDll.so

e0709000-e0715000 rw-p 00000000 00:00 0

f4d00000-f4d21000 rw-p 00000000 00:00 0

f4d21000-f4e00000 ---p 00000000 00:00 0

f4f00000-f4f21000 rw-p 00000000 00:00 0

f4f21000-f5000000 ---p 00000000 00:00 0

 

So far so good.

At same time I am trying to build this vector_scal example on a 32 bit Linux(Ubuntu) there this option CFLAGS=-m32 does not help me. Even when I configure with that option, build and execute,

The log of the execution is as below –

AFTER: First element is 1.000000

AFTER: Last element is 2048.000000   This output suggests the actual scaling kernel is not executed/invoked because the example code does a loop from 1 to 2048 and multiply each scalar by a factor of 3.14(pi).

                                                         Why would the kernel not be invoked and executed is interesting?

 

Waiting for threads to stop...

LEON cycle count = 765

LEON power consumed = 0.0000 mW

*** glibc detected *** /home/movidius/code/moviSimStarPU/trunk/examples/basic_examples/.libs/lt-vector_scal: double free or corruption (!prev): 0x0912d620 ***

======= Backtrace: =========

/lib/tls/i686/cmov/libc.so.6(+0x6b591)[0xb72be591]

/lib/tls/i686/cmov/libc.so.6(+0x6cde8)[0xb72bfde8]

 

Any help on below questions -

1] What is this double free or corruption errors above in both cases?

2] Why in the case 2, the opencl vector scale kernel doesn’t seem to be executed.

 

thanks.