Hi Werner,

Thank you for testing. The bug is in the queue.

Elena
On Feb 16, 2012, at 5:20 AM, Werner Benger wrote:

> Hi Elena,
> 
>  I've tested it with version 1.8.9-snap10, and the behavior is still the 
> same, giving a
> difference of about 386MB RAM usage in my application scenario, depending
> on whether an H5Dclose() is done after H5Dread() or not, based on that
> aforementioned 83MB file.
> 
>      Werner
> 
> 
> On Wed, 15 Feb 2012 17:34:45 +0100, Elena Pourmal <[email protected]> 
> wrote:
> 
> Hi Werner,
> 
> It looks like a bug. I've just entered the issue into our database. 
> 
> When you have a chance, could you please try the latest 1.8.8 to confirm that 
> the issue is still there?
> 
> Thank you!
> Elena
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Elena Pourmal  The HDF Group  http://hdfgroup.org   
> 1800 So. Oak St., Suite 203, Champaign IL 61820
> 217.531.6112
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> 
> 
> On Feb 15, 2012, at 7:18 AM, Werner Benger wrote:
> 
>> Hi,
>> 
>> I'm reading a file of size ~83MB consisting out of 6294 datasets,
>> converting single precision data in the file to double precision in
>> memory, so the memory occupancy would be about 145MB of all data loaded
>> itself. However, once reading a dataset with H5Dread() I leave the
>> data space identifier open, for further usage in case the same dataset
>> needs to be read again later. This leads to some memory overhead of
>> 388MB, which is twice as large as the data that is actually used in
>> memory. When doing an H5Dclose() on the dataset identifier just after
>> the H5Dread() call, this memory overhead does not appear.
>> 
>> Is there a way to free this evidently HDF5-internal memory that is
>> used when reading a dataset? I'd like to keep the dataset identifier
>> available for further usage, but this memory overhead per read is
>> killing memory performance. Calling
>> 
>> H5garbage_collect(void)
>> 
>> doesn't help. I'm using HDF5 version 1.8.4-snap17 , was there any
>> change on such memory management behavior in more recent versions?
>> 
>> 
>>      Werner
>> 
>> -- 
>> ___________________________________________________________________________
>> Dr. Werner Benger                Visualization Research
>> Laboratory for Creative Arts and Technology (LCAT)
>> Center for Computation & Technology at Louisiana State University (CCT/LSU)
>> 211 Johnston Hall, Baton Rouge, Louisiana 70803
>> Tel.: +1 225 578 4809                        Fax.: +1 225 578-5362
> 
> 
> 
> 
> --
> ___________________________________________________________________________
> Dr. Werner Benger Visualization Research
> Laboratory for Creative Arts and Technology (LCAT)
> Center for Computation & Technology at Louisiana State University (CCT/LSU)
> 211 Johnston Hall, Baton Rouge, Louisiana 70803
> Tel.: +1 225 578 4809 Fax.: +1 225 578-5362

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