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Subject: Re: [OMPI devel] mca_pml_ob1_rdma_btls and leave_pinned logic
From: Roman Cheplyaka (roman.cheplyaka_at_[hidden])
Date: 2009-10-05 05:26:28


Okay, I tried Open MPI 1.3.3 and nothing has changed -- OpenIB RDMA
isn't used if mpi_leave_pinned is 0.

2009/10/3 Roman Cheplyaka <roman.cheplyaka_at_[hidden]>:
> Jeff,
> yes, I'll try openmpi-1.3.3 on Monday. However, I had look at the svn
> code before, and haven't noticed any substantial changes in the code
> under the question.
> The reason I'm writing to devel@ (and not just reporting a bug) is
> that I'm interested in how it is _supposed_ to work. Are there people
> who wrote the code (or understand it) on the list?
>
> On 03/10/2009, Jeff Squyres <jsquyres_at_[hidden]> wrote:
>> On Sep 29, 2009, at 1:36 PM, Roman Cheplyaka wrote:
>>
>>> Thanks for your explanation, George. However:
>>> suppose we have leave_pinned = FALSE. Then we go to
>>> mca_mpool_rdma_find. There we try to find suitable registration in the
>>> cache. Suppose we cannot (cache's empty). Then NULL registration is
>>> returned, BTL is skipped and 0 is returned from mca_pml_ob1_rdma_btls.
>>> This way RDMA never happends.
>>>
>>> (To make it clear: this is not some theoretical situation, this is
>>> what I'm actually observing. OpenMPI 1.2.9) Can somebody explain
>>> please?
>>>
>>
>> Sorry for the delay in replying.
>>
>> We actually haven't looked at the 1.2.x code in quite a while -- is it
>> possible for you to upgrade to the 1.3 series?  There have been *many*
>> improvements in the overall code base since the 1.2 series.

-- 
Roman I. Cheplyaka