profile not showing it all?

[Niels van der Velden]

These are the latest nrs concerning the space behaviour of my 
application. Some seem very weird to me. I tested the binaries
on to different hosts.

host1: Pentium4 2,33 Ghz, 512 mb, 1 gig swap. (linux) GHC version 6.2.1

                            | top shows VIRT/RSS/TIME | hc graph shows
----------------------------------------------------------------------
non-profiling bin (RTS -c) | 144mb / 144mb / 1:39   | n.a.
non-profiling bin          | 161mb / 161mb / 1:32   | n.a.
profiling bin (RTS -hc -c) | 188mb / 188mb / 13:59  | 90 mb
profiling bin (RTS -hc)    | 295mb / 295mb / 19:05  | 90 mb


host2: Pentium4 2,00 Ghz, 512 mb, 1 gig swap. (linux) GHC version 6.4

                            | top shows VIRT/RSS/TIME | hc graph shows
----------------------------------------------------------------------
non-profiling bin (RTS -c) | 148mb / 144mb / 2:12   | n.a.
non-profiling bin          | 165mb / 161mb / 1:60   | n.a.
profiling bin (RTS -hc -c) | 621mb / 420mb / 22:06  | 90 mb
profiling bin (RTS -hc)    | 300mb / 295mb / 17:11  | 90 mb

another funny fact is that the profiling bin (RTS -hc -c) could not
finish on my host (Athlon XP 2200, 512mb, 1gig swap. (debian) GHC
version 6.4) because i ran out of 1 gig of virtual memory and was
using 450mb real mem at that moment.

First thing to notice is that in all cases the heap graph was the
same (ignoring time axis). What struck me as surprising was the
enormeous difference in memory consumption between 2 hosts
(that have almost similar hardware, but different GHC version).
This raises some questions i can't answer...

1) Can this different be explained by the version difference of GHC !?

2) How can it be that my own host consumes a ridiculous amount of
memory in comparison to host1; i couldn't even finish the run
because i ran out of 1gig of swap and 512mb memory, while host1
finished the job consuming 188mb (both VIRT and RSS) in 13:59.
Even IF the difference can be explained by the version of GHC.
Even the difference with host2 (that also has GHC 6.4) is still
big.

Niels.

PS ofcourse the binaries were the same everywhere, so was the test
file, etc.