Thanks George,
is valgrind able to mark memory as read only ?
i checked quickly but could not find such a feature
Cheers,
Gilles
On 3/7/2016 11:40 AM, George Bosilca wrote:
Gilles,
memchecker is intended to be used together with some suppression rules.
For the receive the rationale of maki
Gilles,
memchecker is intended to be used together with some suppression rules.
For the receive the rationale of making the buffer unaccessible after the
unpack was to ensure that nobody is touching the memory until we return
from the receive. The buffer was supposed to be made available during t
Folks,
Here is attached a simplified C only version of the test program.
it can be ran with two or one task.
on rhel7, valgrind complains about an invalid read when accessing the
recv buffer after MPI_Recv.
this is pretty odd since :
- the buffer is initialized *before* MPI_Recv is invoked
- M
Something is really weird here ...
right after MPI_Recv, if i
if (cstr[0] != 'H') cout << "bad first character" << endl;
then valgrind complains !
i rewrote the program in C, but if i use subroutines for send(), then
MPI_Send fail because of a NULL communicator ... if i manually inline
send(),
All of those valgrind reports below are from within your code -- not from
within Open MPI.
All Open MPI can do is pass the contents of your message properly; you can
verify that it is being sent and received properly by checking the byte
contents of your received array (e.g., assert that the st
Hey,
Am Donnerstag, 3. März 2016, 17:50:59 CET schrieb Gilles Gouaillardet:
> Florian,
>
> which distro are you running on ?
I'm running Arch.
> if you are not using stock gcc and valgrind, can you tell which version you
> are running ?
> last but not least, how did you configure openmpi ?
ope
Am Mittwoch, 2. März 2016, 16:23:02 CET schrieb Jeff Squyres (jsquyres):
> There's a bunch of places in OMPI where we don't initialize memory because we
> know it doesn't matter (e.g., in padding between unaligned struct members),
> but then that memory is accessed when writing the entire struct
Florian,
which distro are you running on ?
if you are not using stock gcc and valgrind, can you tell which version you
are running ?
last but not least, how did you configure openmpi ?
Cheers,
Gilles
On Thursday, March 3, 2016, Florian Lindner wrote:
> I am still getting errors, even with you
I am still getting errors, even with your script.
I will also try to modified build of openmpi that Jeff suggested.
Best,
Florian
% mpicxx -std=c++11 -g -O0 -Wall -Wextra -fno-builtin-strlen mpi_gilles.cpp &&
mpirun -n 2 ./a.out
Stringlength = 64
1234567890123456789012345678901234567
I was unable to reproduce this in my environment.
here is a slightly modified version of your test program.
buffers are 64 bytes aligned and the string (including the null
terminator) is 64 bytes long,
hopefully, strlen will not complain any more.
Cheers,
Gilles
On 3/3/2016 12:51 AM, Florian
There's a bunch of places in OMPI where we don't initialize memory because we
know it doesn't matter (e.g., in padding between unaligned struct members), but
then that memory is accessed when writing the entire struct down a file
descriptor or memcpy'ed elsewhere in memory...etc. It gets even w
Hello Gilles,
Am Mittwoch, 2. März 2016, 23:36:56 CET schrieb Gilles Gouaillardet:
> Florian,
>
> under the hood, strlen() can use vector instructions, and then read memory
> above the end of the string. valgrind is extremely picky and does warn
> about that.
> iirc, there are some filter options
Florian,
under the hood, strlen() can use vector instructions, and then read memory
above the end of the string. valgrind is extremely picky and does warn
about that.
iirc, there are some filter options not to issue these warnings, but I
forgot the details.
can you try to send "Bonjour" instead o
Hello,
using OpenMPI 1.10.2 and valgrind 3.11.0 I try to use the code below to
send a c++ string.
It works fine, but running through valgrind gives a lot of memory errors,
invalid read of size...
What is going wrong there?
Valgrind output, see below.
Thanks!
Florian
// Compile with: mpicxx
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