Memory Issues

[Daedalus]

I've just installed FS-UAE on an old Lubuntu machine. I can launch the emulation fine as a basic A1200, but I can't seem to allocate any Z-III fast RAM or RTG RAM. When either one is added to the config, the emulation gives an error message that the requested amount of the type of RAM is "larger than maximum reserved 0 (0x0)". This would make me think there wasn't enough RAM on the host machine, however it has 1GB of RAM with only 300MB in use when emulating a basic A1200. Surely adding 16MB of Z-III RAM shouldn't need 700MB of host RAM? Or am I missing something else entirely here?

Thanks, and merry Christmas to all

[jbl007]

On my machine fs-uae allocates 2.5GB of virtual memory even with low end Amiga emulation. (Why?)
If you don't have that much mem, you can use a swap partion of at least that size. If your swap partition is too small and you can't/don't want to change partition layout, you could create a swap file. You need free disk space of course. :-)

cd /
sudo dd if=/dev/zero of=swapfile bs=1M count=3000
sudo mkswap swapfile
sudo swapon swapfile

Should work now...
To make the changes permanent edit /etc/fstab and add the following line:

/swapfile none swap sw 0 0

[Daedalus]

Ah, I'll try that, thanks very much. Only have a 1GB swap partition currently (and adjusting partitions is probably not something I should do after drinking all day). That's crazy though, earlier versions worked fine, and the latest WinUAE (3.4.0) runs fine in Wine with lots more RAM allocated to the Amiga side.

[FrodeSolheim]

FS-UAE "allocates" 2 GB memory at startup via mman, it does not use it, so you don't need 2 GB physical memory for this. Linux will not use actual RAM for the memory pages until the memory pages are used. Right now FS-UAE always allocates memory in a JIT-compatible fashion even though JIT is not enabled, so if it fails to reserve a large contiguous memory area, it will not be able to allocate Zorro III RAM.

(It is possible that with little physical memory, the system will be less happy to mmap large amounts of memory. I haven't examined FS-UAE's behavior in a low-memory environment).

You can attach FS-UAE.log.txt and I can at quickly look at the allocation log lines.

[Daedalus]

Yeah, that looks like it's the case, with 1GB of physical RAM and 1GB of swap it naturally won't be able to reserve 2GB.

I'll try it tomorrow with a larger pagefile and see if that works, I expect it would. I can't find the logfile here, or an option in the GUI to enable it - where is it normally saved?

Thanks!