Re: RamFAST & GS/OS cache

[toddpw@cco.caltech.edu (Todd P. Whitesel)]

David.Empson@bbs.actrix.gen.nz writes:

>Maintaining the cache is the device driver's responsibility, not the FST's.

Of course. But it is the responsibility of the FST (and the user) to tell the
driver what is worth caching.

>read the required blocks.  The driver checks to see if the blocks are
>already in the cache, and if so, copies them out into the buffer
>supplied by the FST.  If they aren't in the cache, the driver reads
>them into the cache and copies them into the FST's buffer.

This is fine IF copying them is faster than reading them. When something is
in the RamFast cache, it is much faster to blast them into memory than it is
to copy them (unless you have a high end accelerator).

>What are you suggesting as an enhancement?  That the in-memory copying
>be avoided by having the FST refer directly to the data in the cache?

Damn Straight. What advantage is there in doing it any other way?

Todd Whitesel
toddpw @ cco.caltech.edu