Benno Senoner wrote:
...
>
> 1)
> my frist BIG QUESTION is if there is a design flaw in malloc() or not:
No, malloc() should return nil if the memory requested cannot be backed
by real storage. However, some unicies are configured to perform just as
you discovered
because much of the memory "allocated" is not actually touched. I'm not
sure what the Linux levers are but I'd expect there is a way to switch on
available memory accounting. The other trick on IRIX was the ability to
add an amount of swap memory that was actually not backed. The size of
this kind of swap was tuned by the user to get the best behaviour.
Pedantic users didn't allow this kind over over-booking of backing store.
If you are allocating such big chunks and you have a multi-user system,
it may actually be preferable to allocate your data from a mmap()ed file
so you can guarentee the availability of backing store. I have yet to
see a version of "amalloc()" for Linux, but that would be helpful if you
want to malloc out of a mapped file. It could also be used as a fast IPC
mechanism but your malloc() would need to use relative adresses
to be really safe.
I'm curious why you would send this question through linux-raid ?
