Re: [Qemu-devel] [PATCH] Save memory allocation in the elf loader

[Alexander Graf]

On 19.02.2013, at 15:41, Fabien Chouteau wrote:

> The current elf loader uses too much memory. For example, I have a
> executable with a bss section of 400 MB and I set the ram size to 512
> MB. Qemu uses about 780MB of RAM (which is fine), but there's a peak at
> 1.6 GB during initialization (this is not fine).
> 
> This patch fixes two things:
> 1) do not allocate each elf program twice.
> 2) do not allocate memory for areas that are only zeros.
> 
> For this we need a new field in Rom: "datasize" which is the size of the
> allocated data. If datasize is less than romsize, it means that the area
> from datasize to romsize is filled with zeros.
> 
> Signed-off-by: Fabien Chouteau <address@hidden>

In the long run, we should make the elf loader not use the rom framework at 
all, but instead provide its own reset functions.

However, for now I think this is a valuable optimization. Thanks for looking 
into it :).

Applied to ppc-next.


Alex