On Fri 13-07-18 07:52:40, Baoquan He wrote: > Hi Michal, > > On 07/12/18 at 02:32pm, Michal Hocko wrote: [...] > > I am not able to find the beginning of the email thread right now. Could > > you summarize what is the actual problem please? > > The bug is found on x86 now. > > When added "kernelcore=" or "movablecore=" into kernel command line, > kernel memory is spread evenly among nodes. However, this is right when > KASLR is not enabled, then kernel will be at 16M of place in x86 arch. > If KASLR enabled, it could be put any place from 16M to 64T randomly. > > Consider a scenario, we have 10 nodes, and each node has 20G memory, and > we specify "kernelcore=50%", means each node will take 10G for > kernelcore, 10G for movable area. But this doesn't take kernel position > into consideration. E.g if kernel is put at 15G of 2nd node, namely > node1. Then we think on node1 there's 10G for kernelcore, 10G for > movable, in fact there's only 5G available for movable, just after > kernel. OK, I guess I see that part. But who is going to use movablecore along with KASLR enabled? I mean do we really have to support those two obscure command line parameters for KASLR? In fact I would be much more concerned about memory hotplug and pre-defined movable nodes. Does the current KASLR code work in that case? -- Michal Hocko SUSE Labs
