The ABINIT Users Mailing List ( CLOSED )

[Enrico Bellotti <bellotti@bu.edu>]

Greetings to all,
just as a minor contribution i would like to point out that some compilers 
have a different behavior when it comes to "garbage collection" for 
structure that are dynamically allocated. I have looked at this problem for 
the DEC Fortran Compiler, Intel Fortran Compiler and PGI. In general the 
first two will do a very good job in reallocating the memory for structures 
no longer used while the PGI keeps reallocating new memory. This is 
particularly problematic in subroutines that allocate local data 
structures. If the data structures are not explicitly de-allocated before 
exiting at the next call, the data-structure is allocated once again. The 
DEC and Intel compiler will reuse (or try to) the same memory space while 
the PGI will reallocate different memory pages. For the PGI the net results 
is a out-of-memory problem even if the machine has a lot of RAM. I am not 
sure what the behavior of the g95 is. Hope this is useful.
Regards.
Enrico



|||||  Enrico Bellotti, Ph.D.
_ _   Assistant Professor
 . .   Boston University
  |    Electrical & Computer Engineering Dept.
\_/   8 Saint Mary's Street
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