/tmp on tmpfs

[Chris Murphy]

On Apr 6, 2012, at 8:03 AM, Vratislav Podzimek wrote:
>>> That a lost fight, because one of /tmp's primary purposes is to 
>> temporarily store almost arbitrarily huge amounts of data, instead of 
>> storing them in memory.
> This is the key overlooked fact.

What happens to /tmp on tmpfs when real memory and swap are completely consumed? I think the key overlooked fact is the possibility some application asks for a lot more /tmp space than is ever reserved for swap. Example:

I'd expect Brisera to produce an ~9GB temp file when burning a fully consumed dual-layer DVD. Incorrect assumption? Minimum requirements for Fedora 16, 1152MB RAM. That translates into what default for swap space? Is this at least 4GB, or whatever the minimum amount of swap needed for tmpfs when full to overflow to?

Does anyone know what the behavior of Scribus, GIMP, Cinelerra, etc. are when it comes to temp space requirements? I could see GIMP arbitrarily want multiple gigabytes of space, well beyond physical RAM plus that reserved for swap space.


Chris Murphy