Re: [uml-user] tmpfs thing & mlockall

[Christian J. <chr...@et...>]

At 10:13 Uhr +0100 21.09.2003, James Stevenson wrote:
>  > - Why does uml implement RAM in files in tmpfs? Why not just normal
>  > malloc'ed memory? At least I wouldn't need to use tmpfs (which would
>>  be a little simplification in the setup) - it'll end up in RAM or
>>  swap anyways, so..
>
>because if you create the vm file in /tmp or somewhere else on the disk
>the host will continuously write back the memory image into the disk
>file. Which causes a massive slowdown. ..

Yes, I think you misunderstood me, maybe I was unclear. What I wanted 
to ask is not why tmpfs is better than a normal filesystem for /tmp, 
but why uml doesn't use malloc instead of mmap to a tmp file. I 
suggest that malloc and mmap to a file on tmpfs should have equal 
performance (maybe malloc even sligtly better), but malloc does have 
less administrative burden / is less awkward.

Christian.