On Fri, Mar 10, 2017 at 09:10:53PM +0200, Michael S. Tsirkin wrote: > > I completely agree with you that we should be able to pass a hugepage > > as a single chunk. Also we shouldn't assume that host and guest have > > the same page size. I think we can come up with a scheme that actually > > lets us encode that into a 64-bit word, something like this: > > > > bit 0 clear => bits 1-11 encode a page count, bits 12-63 encode a PFN, page size 4k. > > bit 0 set, bit 1 clear => bits 2-12 encode a page count, bits 13-63 encode a PFN, page size 8k > > bits 0+1 set, bit 2 clear => bits 3-13 for page count, bits 14-63 for PFN, page size 16k. > > bits 0-2 set, bit 3 clear => bits 4-14 for page count, bits 15-63 for PFN, page size 32k > > bits 0-3 set, bit 4 clear => bits 5-15 for page count, bits 16-63 for PFN, page size 64k > > huge page sizes go up to gigabytes. There was supposed to be a '...' there. For a 16GB hugepage (largest size I know of today), that'd be: bits 0-21 set, 22 clear, 23-33 page count, 34-63 PFN, page size 16G -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
