[SCore-users] Score malloc

[Jens Klaas]

Der all,
I installed a PC cluster, 32 nodes, dual AMD procs, 1GB of memory per box. 
Some of our user like to use as much memory as possible. 
They realized a strange behavior of the score malloc routine.

I took a deeper look at the problem and made some tests. 

a) Allocating memory and giving it free without using it. 

I got a maximum 1090 MB for each of the 64 per processes

b) Allocating memory, filling it with 'X' and giving it free.

For SCORE malloc, I got

    1 CPU          770 MB - 850 MB 
    32x1 CPU    440 MB                     <- expected 770-850 MB
    32x2 CPUs   240 MB		      <- expected 385-425 MB

c) allocating memory as many small parts (100 X 10 MB), didn't give it free.

Fore Score malloc, I got 

 
    1 CPU         850 MB
    32x1 CPU    820 MB
    32x2 CPUs   420 MB

There seems to be a problem to allocate big blocks of memory.

Is it a bug?
Does any of you already got problems with it?

cu
	Jens