Re: [RFC 0/2] kvm: Transcendent Memory (tmem) on KVM

From: Avi Kivity
Date: Thu Mar 15 2012 - 15:08:21 EST


On 03/15/2012 08:02 PM, Konrad Rzeszutek Wilk wrote:
> >
> > Nice. This takes care of the tail-end of the streaming (the more
> > important one - since it always involves a cold copy). What about the
> > other side? Won't the read code invoke cleancache_get_page() for every
> > page? (this one is just a null hypercall, so it's cheaper, but still
> > expensive).
>
> That is something we should fix - I think it was mentioned in the frontswap
> email thread the need for batching and it certainly seems required as those
> hypercalls aren't that cheap.

In fact when tmem was first proposed I asked for two changes - make it
batchable, and make it asynchronous (so we can offload copies to a dma
engine, etc). Of course that would have made tmem significantly more
complicated.

--
error compiling committee.c: too many arguments to function

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