On Mon, Mar 19, 2012 at 01:42:08PM +0200, Avi Kivity wrote: > Extra work, and more slowness until they get rebuilt. Why not migrate > entire large pages? The main problem is the double copy, first copy for migrate, second for khugepaged. This is why we want it native over time. So it also only stops the accesses to the pages for a shorter period of time. > I agree with this, but it's really widespread throughout the kernel, > from interrupts to work items to background threads. It needs to be > solved generically (IIRC vhost has some accouting fix for a similar issue). Exactly. > It's the standard space/time tradeoff. Once solution wants more > storage, the other wants more faults. I didn't grow it much more than memcg, and at least if you boot on NUMA hardware you'll be sure to use AutoNUMA. The fact it's in the struct page it's an implementation detail, it'll only be allocated if the kernel is booted on NUMA hardware later. -- 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>