Chromium OS limited to 2Gb memory?

[Nikita Kostylev]

Hi,

I'm running chromium-os image under kvm with 3Gb memory allocated.

Reason I'm trying to allocate >2Gb memory is to load debug chrome (2Gb) into gdb.

sudo kvm -m 3072 -std-vga -net nic -net user -redir tcp:922::22 ...

But chromium-os sees only 2 Gb.

According https://help.ubuntu.com/community/KVM/Installation 64bit host systems should be able to allocate more than 2 Gb.

Is that limited on chromium-os side?

Side question:

Last time we've tried enabling swap on chromium-os and found that that it's disabled on kernel level. Is that's still the case?

--
Nikita

[Hugh Dickins]

On Tue, Aug 3, 2010 at 7:46 AM, Nikita Kostylev <nkos...@chromium.org> wrote:
> Hi,
> I'm running chromium-os image under kvm with 3Gb memory allocated.
> Reason I'm trying to allocate >2Gb memory is to load debug chrome (2Gb) into
> gdb.
> sudo kvm -m 3072 -std-vga -net nic -net user -redir tcp:922::22 ...
> But chromium-os sees only 2 Gb.
> According https://help.ubuntu.com/community/KVM/Installation 64bit host
> systems should be able to allocate more than 2 Gb.
> Is that limited on chromium-os side?

The kernel .config has CONFIG_VMSPLIT_2G_OPT=y selected, to suit
targets of that size: if you want to use more, please try changing to
CONFIG_VMSPLIT_3G_OPT or CONFIG_VMSPLIT_3G or CONFIG_HIGHMEM4G.

> Side question:
> Last time we've tried enabling swap on chromium-os and found that that it's
> disabled on kernel level. Is that's still the case?

Yes, that's still the case, CONFIG_SWAP is not set: we're still
inclined to think that it will be better to fix memory leaks than
spill over into swap. But that's not a dogmatic position, and you're
welcome to try changing to CONFIG_SWAP=y -
/sbin/swapon appears to be there, presumably you'd want to set up a
swapfile on the stateful partition.

Hugh