[Lustre-devel] lustre-to-LNET API: big non-aligned bulk transfers

[jan julian]

Just so your aware, the21057  bugzilla's assignment yesterday was as  
follows.  Who can I get to move this forward so that I can
exchange messages with someone.

People
Reporter:	pravin shelar <pravin.shelar at sun.com>
Assigned To:	pravin shelar <pravin.shelar at sun.com>
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On Oct 16, 2009, at 8:49 AM, Maxim V. Patlasov wrote:

> Eric,
>
> To make things 100% clear - did you answer positively ('It  
> should...') because there are some lustre use-cases for such  
> transfers or just because it would be natural for LNET to support  
> both aligned and not-aligned big bulk transfers?
>
> Thanks in advance,
> Maxim
>
> On 10/14/2009 09:22 PM, Eric Barton wrote:
>>
>> Maxim,
>>
>> It should support such transfers, but you have to be careful about
>> the number of fragments this can introduce.  This issue has already
>> been observed in routers, which buffer LNET message payloads at
>> the same page offset, irrespective of the sender's page offset (of
>> which it has no knowledge).  For example, this can force the o2iblnd,
>> if configured to pre-map all memory, to need double the number of  
>> RDMA
>> fragments and therefore fail the transfer.  Chat with Liang - he  
>> knows
>> all about this...
>>
>>     Cheers,
>>               Eric
>>
>>
>>> -----Original Message-----
>>> From: lustre-devel-bounces at lists.lustre.org [mailto:lustre-devel-bounces at lists.lustre.org 
>>> ] On Behalf Of Maxim V.
>>> Patlasov
>>> Sent: 14 October 2009 8:23 AM
>>> To: lustre-devel at lists.lustre.org
>>> Subject: [Lustre-devel] lustre-to-LNET API: big non-aligned bulk  
>>> transfers
>>>
>>> Hi lustre-devel,
>>>
>>> I'd like to gather some opinions about the following question:
>>>
>>> Is it allowed or possible for lustre to submit relatively big bulk
>>> transfer request (e.g. >512K) to LNET layer when offset in the very
>>> first page to fetch bulk data from (on sender side) is not equal  
>>> to the
>>> offset in the very first page to store data (on receiver side)? In  
>>> the
>>> other words - should LNET support such transfers?
>>>
>>> Thanks in advance,
>>> Maxim
>>> _______________________________________________
>>> Lustre-devel mailing list
>>> Lustre-devel at lists.lustre.org
>>> http://lists.lustre.org/mailman/listinfo/lustre-devel
>>>
>>
>>
>
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> Lustre-devel at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-devel

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