Hi!

quoted text
> > > Nevertheless, frontswap works great today with a bare-metal
> > > hypervisor.  I think it stands on its own merits, regardless
> > > of one's vision of future SSD/memory technologies.
> > 
> > Even when frontswapping to RAM on a bare metal hypervisor it makes
> > sense
> > to use an async API, in case you have a DMA engine on board.
> 
> When pages are 2MB, this may be true.  When pages are 4KB and 
> copied individually, it may take longer to program a DMA engine 
> than to just copy 4KB.
> 
> But in any case, frontswap works fine on all existing machines
> today.  If/when most commodity CPUs have an asynchronous RAM DMA
> engine, an asynchronous API may be appropriate.  Or the existing
> swap API might be appropriate. Or the synchronous frontswap API
> may work fine too.  Speculating further about non-existent
> hardware that might exist in the (possibly far) future is irrelevant
> to the proposed patch, which works today on all existing x86 hardware
> and on shipping software.

If we added all the apis that worked when proposed, we'd have
unmaintanable mess by about 1996.

Why can't frontswap just use existing swap api?
							Pavel

-- 
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