On Mon 13-03-17 11:31:10, Igor Mammedov wrote: > On Fri, 10 Mar 2017 14:58:07 +0100 [...] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0x3fffffff] > > [ 0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x40000000-0x7fffffff] > > [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x27fffffff] > > hotplug > > [ 0.000000] NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem > > 0x00100000-0x3fffffff] -> [mem 0x00000000-0x3fffffff] > > [ 0.000000] NODE_DATA(0) allocated [mem 0x3fffc000-0x3fffffff] > > [ 0.000000] NODE_DATA(1) allocated [mem 0x7ffdc000-0x7ffdffff] > > [ 0.000000] Zone ranges: > > [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] > > [ 0.000000] DMA32 [mem 0x0000000001000000-0x000000007ffdffff] > > [ 0.000000] Normal empty > > [ 0.000000] Movable zone start for each node > > [ 0.000000] Early memory node ranges > > [ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009efff] > > [ 0.000000] node 0: [mem 0x0000000000100000-0x000000003fffffff] > > [ 0.000000] node 1: [mem 0x0000000040000000-0x000000007ffdffff] > > > > so there is neither any normal zone nor movable one at the boot time. > it could be if hotpluggable memory were present at boot time in E802 table > (if I remember right when running on hyperv there is movable zone at boot > time), > > but in qemu hotpluggable memory isn't put into E820, > so zone is allocated later when memory is enumerated > by ACPI subsystem and onlined. > It causes less issues wrt movable zone and works for > different versions of linux/windows as well. > > That's where in kernel auto-onlining could be also useful, > since user would be able to start-up with with small > non removable memory plus several removable DIMMs > and have all the memory onlined/available by the time > initrd is loaded. (missing piece here is onling > removable memory as movable by default).
Why we should even care to online that memory that early rather than making it available via e820? > > Then I hotplugged 1G slot > > (qemu) object_add memory-backend-ram,id=mem1,size=1G > > (qemu) device_add pc-dimm,id=dimm1,memdev=mem1 > You can also specify node a pc-dimm goes to with 'node' property > if it should go to other then node 0. > > device_add pc-dimm,id=dimm1,memdev=mem1,node=1 thanks for the tip > > unfortunatelly the memory didn't show up automatically and I got > > [ 116.375781] acpi PNP0C80:00: Enumeration failure > it should work, > do you have CONFIG_ACPI_HOTPLUG_MEMORY enabled? No I didn't. Thanks, good to know! -- Michal Hocko SUSE Labs _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
