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Subject: Re: [OMPI users] Memchecker report on v1.3b2 (includes potential bug reports)
From: George Bosilca (bosilca_at_[hidden])
Date: 2008-11-19 13:20:54


On Nov 19, 2008, at 10:18 , François PELLEGRINI wrote:

>> 4) Well, this sounds reasonable, but according to the MPI-1 standard
>> (see page 40 for non-blocking send/recv, a more detailed
>> explanation in
>> page 30):
>>
>> "A nonblocking send call indicates that the system may start copying
>> data out of the send buffer. The sender should */not access*/ any
>> part
>> of the send buffer after a nonblocking send operation is called,
>> until
>> the send completes."
>>
>> So before calling MPI_Wait to complete an isend operation, any
>> access to
>> the send buffer is illegal. It might be a little strict, but we
>> have to
>> do what the standard says.

This have been changed in the new version of the MPI standard (2.1).
There is no restriction anymore regarding the read operations on the
buffers used for non-blocking sends.

We should modify the memchecker accordingly.

   george.