Heiko Carstens <heiko.carstens@xxxxxxxxxx> writes: > On Mon, Feb 27, 2017 at 11:02:09AM +0100, Vitaly Kuznetsov wrote: >> A couple of other thoughts: >> 1) Having all newly added memory online ASAP is probably what people >> want for all virtual machines. Sorry, obviously missed 'x86' in the above statement. > > This is not true for s390. On s390 we have "standby" memory that a guest > sees and potentially may use if it sets it online. Every guest that sets > memory offline contributes to the hypervisor's standby memory pool, while > onlining standby memory takes memory away from the standby pool. > > The use-case is that a system administrator in advance knows the maximum > size a guest will ever have and also defines how much memory should be used > at boot time. The difference is standby memory. > > Auto-onlining of standby memory is the last thing we want. > This is actually a very good example of why we need the config option. s390 kernels will have it disabled. -- Vitaly -- 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>
