Pharaoh . escreveu:
Hi
I have a machine with 1 GB RAM and 1 GB swap area and it is a 32-bit
machine.
For fun, I tried to allocate memory dynamically by using malloc in a
loop till there is
no memory avilable. I ended up allocating 2 GB memory. My inference
is, total memory
allocated can be equal to size of RAM + size of SWAP at max.
Afaik, for a 32 - bit machine we can not address more than 2^32
addresses. Now, If I
have another machine with 1 GB RAM and 4 GB swap then, as per above
inference I
should be able to allocated 5 GB memory at max ! Out of this only
lower 4 GB will be
addressable.
Is there some loophole in the above argument?
Yes. The kernel establishes a virtual address space for a given process of
4GB (and map both the kernel and the app code/data within this area).
This way you will not be able to allocate 5GB no matter how much RAM or
swap you have.
Fabiano
Regards,
Pharaoh.
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