[mpich-discuss] COMM_SELF and collective IO

[burlen]

Actually, not quite. But if we can put that aside for the moment. Is 
there a significant downside to using COMM_SELF + MPI_File_read_all 
compared to just MPI_File_read?

Rajeev Thakur wrote:
> You will have the same if you use COMM_SELF for one and COMM_WORLD for
> the other. You don't want to use COMM_SELF for both. 
>
>   
>> -----Original Message-----
>> From: mpich-discuss-bounces at mcs.anl.gov 
>> [mailto:mpich-discuss-bounces at mcs.anl.gov] On Behalf Of burlen
>> Sent: Friday, October 16, 2009 7:22 PM
>> To: mpich-discuss at mcs.anl.gov
>> Subject: Re: [mpich-discuss] COMM_SELF and collective IO
>>
>> I could then I will have to have two codes with only a one 
>> line difference.
>>
>> Rajeev Thakur wrote:
>>     
>>> Why don't you just use MPI_File_read instead?
>>>
>>> Rajeev
>>>
>>>   
>>>       
>>>> -----Original Message-----
>>>> From: mpich-discuss-bounces at mcs.anl.gov 
>>>> [mailto:mpich-discuss-bounces at mcs.anl.gov] On Behalf Of burlen
>>>> Sent: Friday, October 16, 2009 5:39 PM
>>>> To: mpich-discuss at mcs.anl.gov
>>>> Subject: [mpich-discuss] COMM_SELF and collective IO
>>>>
>>>> I have an io code that uses the subarray type. I use the 
>>>>         
>> collective 
>>     
>>>> IO function, MPI_File_read_all. Now, I have a use case where each 
>>>> process needs to read independently of the others. What I 
>>>>         
>> am tempted 
>>     
>>>> to do is change the communicator to MPI_COMM_SELF and use the same 
>>>> code. I suspect that this is a bad idea. Is it?
>>>>
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>>>>     
>>>>         
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>>     
>
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