On 3/23/20 5:35 PM, Aurelien Jarno wrote:
Hi,
Sorry for the delay, I just want to give some more details about the
Debian.
On 2020-03-14 10:09, Philippe Mathieu-Daudé wrote:
IIUC today all distributions supporting MIPS ports are building their MIPS
packages on QEMU instances because it is faster than the native MIPS
hardware they have.
Actually Debian requires that packages are built on real hardware. We
have a mix of Loongson 3 and Octeon 3 based build daemons. They all have
8GiB of RAM.
Since one (or two?) years, some binaries (Linux kernel? QEMU?) are failing
to link because the amount of guest memory is restricted to 2GB (probably
advance of linker techniques, now linkers use more memory).
The problem happens with big packages (e.g. ceph which is a dependency
of QEMU). The problem is not the physical memory issue, but the virtual
address space, which is limited to 2GB for 32-bit processes. That's why
we do not have the issue for the 64-bit ports.
YunQiang, is this why you suggested this change?
See:
- https://www.mail-archive.com/debian-mips@lists.debian.org/msg10912.html
-
https://alioth-lists.debian.net/pipermail/pkg-rust-maintainers/2019-January/004844.html
I believe most of the QEMU Malta board users don't care it is a Malta board,
they only care it is a fast emulated MIPS machine.
Unfortunately it is the default board.
However 32-bit MIPS port is being dropped on Debian:
https://lists.debian.org/debian-mips/2019/07/msg00010.html
The 32-bit big endian port has been dropped after the Buster (10)
release and won't be available for the Bullseye release (11). The
32-bit little endian port is still available, but it's difficult to keep
it alive given the 2GB limit.
Maybe we can sync with the Malta users, ask them to switch to the Boston
machines to build 64-bit packages, then later reduce the Malta board to 1GB.
(The Boston board is more recent, but was not available at the time users
started to use QEMU to build 64-bit packages).
Might it be easier starting introducing a malta-5.0 machine restricted to
1GB?
In any case having an easy way to simulate machines with more than 2GB
of RAM in QEMU would be great.
You mean on MIPS64, right?
I see the Boston is limited to 1/2GB, probably due to code started
copy/pasted on the Malta. I don't know (without having to refer to
datasheets) the maximum amount of DRAM the Boston board can handle, but
it should be more than 2GB.
Cheers,
Aurelien
