DragonFly kernel List (threaded) for 2003-09
Re: Ridiculous idea: Cache as ramdisk?
Matthew Dillon wrote:
> [ ... great explanations snipped 8-) ... ]
The MFS filesystem comes fairly close to doing this already since
its backing store is simply the memory associated with a process, but
it has the disadvantage of causing data to be stored in memory twice
(once in the VM / buffer cache, once in the MFS's procs memory space).
Despite the duplication of data, the fact that MFS filesystems do not
automaticaly flush data to a physical storage device has proven to be
a huge performance advantage over the years.
So, in short, we already have the pieces, we just have to get them to
fit together in a reasonable way.
Well, the problem about storing data twice will only affect us
as long as we don't have a Slab Cache, [Bonwick94, Bonwick2001]
but once that is in place, we will be much better off, memory