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Subject: Re: [OMPI users] [Fwd: mpi alltoall memory requirement]
From: Viral Mehta (viral.vkm_at_[hidden])
Date: 2009-04-23 13:35:20


yes of course i m sure about wellness of providers.... and i m using
ofed-1.4.1-rc3
i m running 24 proc per node on 8 node cluster..... so as i showed in
calculation that i require 36G mem.....
i just need to know if my calculation has not some obvious flaw and/or if i
m missing anything about setting up system environment or anything like that

On Thu, Apr 23, 2009 at 10:36 PM, gossips J <polk678_at_[hidden]> wrote:

> What is the NIC you use?
> What OFED build?
> Are you sure about wellness of provider lib/drivers..?
>
> It is strange that you get out of mem in all to all tests... should not
> happen on 32G system,..!!!
>
> -polk.
>
> On 4/23/09, viral.vkm_at_[hidden] <viral.vkm_at_[hidden]> wrote:
>
>> or any link which helps to understand system reuirement for certain test
>> scenario ..
>>
>> On Apr 23, 2009 12:42pm, viral.vkm_at_[hidden] wrote:
>> > Hi
>> > Thanks for your response.
>> > However, I am running
>> > mpiexec .... -ppn 24 -n 192 /opt/IMB-MPI1 alltaoll -msglen /root/temp
>> >
>> > And file /root/temp contains entry upto 65535 size only. That means
>> alltoall test will run upto 65K size only
>> >
>> > So, in that case I will require very less memory but then in that case
>> also test is running out-of-memory. Please help someone to understand the
>> scenario.
>> > Or do I need to switch to some algorithm or do I need to set some other
>> environment variables ? or anything like that ?
>> >
>> > On Apr 22, 2009 6:43pm, Ashley Pittman ashley_at_[hidden]> wrote:
>> > > On Wed, 2009-04-22 at 12:40 +0530, vkm wrote:
>> > >
>> > >
>> > >
>> > > > The same amount of memory required for recvbuf. So at the least each
>> > >
>> > > > node should have 36GB of memory.
>> > >
>> > > >
>> > >
>> > > > Am I calculating right ? Please correct.
>> > >
>> > >
>> > >
>> > > Your calculation looks correct, the conclusion is slightly wrong
>> > >
>> > > however. The Application buffers will consume 36Gb of memory, the rest
>> > >
>> > > of the application, any comms buffers and the usual OS overhead will
>> be
>> > >
>> > > on top of this so putting only 36Gb of ram in your nodes will still
>> > >
>> > > leave you short.
>> > >
>> > >
>> > >
>> > > Ashley,
>> > >
>> > >
>> > >
>>
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
>
>

-- 
Thanks,
Viral Mehta