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[netCDF #OBW-613992]: Possible memory leak in nf90_get_var (netcdf/4.3.0)
- Subject: [netCDF #OBW-613992]: Possible memory leak in nf90_get_var (netcdf/4.3.0)
- Date: Tue, 29 Dec 2015 10:27:56 -0700
Hello Jan,
Thank you for the comprehensive report; it will make investigating this much
faster. Out of curiosity, what version of netcdf-fortran were you using? The
current releases of netcdf-c and netcdf-fortran are 4.3.3.1 and 4.4.2,
respectively. It appears that you are using an older netcdf-c library, I am
curious if these issues still occur in the most recent version.
Thanks again for the test cases; I will have to investigate this more closely.
Have a great day!
-Ward
> Dear Unidata support,
>
> I've run into a problem that is possibly a memory leak in the netCDF library
> (netcdf/4.3.0). When I use nf90_get_var to read from a series of netCDF
> archives, eventually all RAM on the machine ends up being used, even though
> every netCDF archive is closed before the next one is opened (chunk cache is
> not the cause).
>
> I attached a demonstration code (memory_leak_demo.tgz). It can be compiled by
> running the compile.sh script, after setting the FC (Fortran compiler) and
> NETCDF (path to netCDF library) environment variables. The demonstration code
> has two executables:
>
> memory_leak_demo_1: Creates one netCDF archive with data, and reads the data
> from the archive once.
>
> memory_leak_demo_2 : Creates ten netCDF archives with data, and reads the
> data from each of the ten archives once.
>
> The executables use only one array (of the same size) to read the data, and
> hence should use the same amount of memory - but they don't. I attached PBS
> output logs for the two executables (compiled with intel/14.0.2):
>
> MEMORY_LEAK_DEMO_1_THEIA.sh.o5600419
> MEMORY_LEAK_DEMO_2_THEIA.sh.o5600420
>
> Comparing these, memory_leak_demo_2 uses about 5 times more memory than
> memory_leak_demo_1. I suspect this indicates a memory leak (unless I am
> missing something crucial).
>
> Jan
>
>
>
Ticket Details
===================
Ticket ID: OBW-613992
Department: Support netCDF
Priority: Normal
Status: Closed