Dave:

I am stumped as to why your environment sees the compiler error and mine
doesn't.  Do you happen to have the C_INCLUDE_PATH set?  If so, will you
send me its value?


Were you able to try the svn trunk version in your environment?

Becky

On Tue, Jun 16, 2015 at 1:24 PM, Becky Ligon <[email protected]> wrote:

> Dave and Rob:
>
> Yes.  The modified open() via the usrint library allows a program to
> specify things like strip size and number of datafiles on an open that has
> the O_CREAT flag set.  fcntl() could not be used in this situation, because
> once a file is created via OrangeFS these properties cannot be changed.
>
> Dave:
>
> Thanks for the glibc info.  Still trying to determine in which version of
> glibc this problem occurs.
>
> Becky
>
> On Tue, Jun 16, 2015 at 9:59 AM, Rob Latham <[email protected]> wrote:
>
>>
>>
>> On 06/16/2015 08:52 AM, Dave Love wrote:
>>
>>> Rob Latham <[email protected]> writes:
>>>
>>>  I wasn't involved in this feature, but it looks like OrangeFS is
>>>> taking advantage of open() being declared with variable length
>>>> arguments to pass in a fourth "hint" parameter.
>>>>
>>>
>>> I'm still puzzled on what system that does anything.
>>>
>>
>> In the old days you had two ways to access PVFS:
>>
>> - make a round trip through the kernel module, bouncing through quite a
>> few userspace-kernelspace copies.
>>
>> - contact PVFS servers directly through the "system interface".  The one
>> real client for the system interface is ROMIO's PVFS driver, but some of
>> the early utilities would use it too (maybe still do?)
>>
>> OrangeFS provides a third way: link in with the orangfs library and now
>> the posix open/close/read/write system calls become OrangeFS calls. no code
>> changes needed.  You might not get a lot of parallelism out of it, but it
>> makes many-task non-MPI workloads (like Hadoop) easier to support.
>>
>> So, that fourth argument was a (sneaky!) attempt to set some PVFS
>> parameters without changing the posix-like API.  The less-sneaky but gross
>> way to do this for most file systems is via fcntl() operations, but fcntl
>> is an awful interface.
>>
>> ==rob
>>
>> --
>> Rob Latham
>> Mathematics and Computer Science Division
>> Argonne National Lab, IL USA
>> _______________________________________________
>> Pvfs2-users mailing list
>> [email protected]
>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>>
>
>
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