On 03/19/2012 10:03 PM, Peter Zijlstra wrote: > On Mon, 2012-03-19 at 14:16 +0200, Avi Kivity wrote: > > > Afaik we do not use dma engines for memory migration. > > > > We don't, but I think we should. > > ISTR we (the community) had this discussion once. I also seem to > remember the general consensus being that DMA engines would mostly > likely not be worth the effort, although I can't really recall the > specifics. > > Esp. for 4k pages the setup of the offload will likely be more expensive > than actually doing the memcpy. If you're copying a page, yes. If you're copying a large vma, the per-page setup cost is likely to be very low. Especially if you're copying across nodes. -- error compiling committee.c: too many arguments to function -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>