On Wed 23-05-18 12:26:43, Oscar Salvador wrote: > On Wed, May 23, 2018 at 10:16:09AM +0200, Michal Hocko wrote: > > On Wed 23-05-18 09:52:39, Michal Hocko wrote: > > [...] > > > Yeah, the current code is far from optimal. We > > > used to have a retry count but that one was removed exactly because of > > > premature failures. There are three things here > > > 1) zone_movable should contain any bootmem or otherwise non-migrateable > > > pages > > > 2) start_isolate_page_range should fail when seeing such pages - maybe > > > has_unmovable_pages is overly optimistic and it should check all > > > pages even in movable zones. > > > 3) migrate_pages should really tell us whether the failure is temporal > > > or permanent. I am not sure we can do that easily though. > > > > 2) should be the most simple one for now. Could you give it a try? Btw. > > the exact configuration that led to boothmem pages in zone_movable would > > be really appreciated: > > Here is some information: > > ** Qemu cmdline: > > # qemu-system-x86_64 -enable-kvm -smp 2 -monitor pty -m 6G,slots=8,maxmem=8G -numa node,mem=4096M -numa node,mem=2048M ... > # Option movablecore=4G (cmdline) > > ** e820 map and some numa information: > > linux kernel: BIOS-provided physical RAM map: > linux kernel: BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable > linux kernel: BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved > linux kernel: BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved > linux kernel: BIOS-e820: [mem 0x0000000000100000-0x00000000bffdffff] usable > linux kernel: BIOS-e820: [mem 0x00000000bffe0000-0x00000000bfffffff] reserved > linux kernel: BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved > linux kernel: BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved > linux kernel: BIOS-e820: [mem 0x0000000100000000-0x00000001bfffffff] usable > linux kernel: NX (Execute Disable) protection: active > linux kernel: SMBIOS 2.8 present. > linux kernel: DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org > linux kernel: Hypervisor detected: KVM > linux kernel: e820: update [mem 0x00000000-0x00000fff] usable ==> reserved > linux kernel: e820: remove [mem 0x000a0000-0x000fffff] usable > linux kernel: last_pfn = 0x1c0000 max_arch_pfn = 0x400000000 > > linux kernel: SRAT: PXM 0 -> APIC 0x00 -> Node 0 > linux kernel: SRAT: PXM 1 -> APIC 0x01 -> Node 1 > linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00000000-0x0009ffff] > linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x00100000-0xbfffffff] > linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0x13fffffff] > linux kernel: ACPI: SRAT: Node 1 PXM 1 [mem 0x140000000-0x1bfffffff] > linux kernel: ACPI: SRAT: Node 0 PXM 0 [mem 0x1c0000000-0x43fffffff] hotplug > linux kernel: NUMA: Node 0 [mem 0x00000000-0x0009ffff] + [mem 0x00100000-0xbfffffff] -> [mem 0x0 > linux kernel: NUMA: Node 0 [mem 0x00000000-0xbfffffff] + [mem 0x100000000-0x13fffffff] -> [mem 0 > linux kernel: NODE_DATA(0) allocated [mem 0x13ffd6000-0x13fffffff] > linux kernel: NODE_DATA(1) allocated [mem 0x1bffd3000-0x1bfffcfff] Could you also paste "Zone ranges:" and the follow up messages? >From the zoneinfo it seems the movable zone got placed to both nodes. And only Node0 is marked as hotplugable so early allocations can be placed to Node1. > ** /proc/zoneinfo [...] > Node 0, zone Movable > pages free 160140 > min 1823 > low 2278 > high 2733 > spanned 262144 > present 262144 > managed 245670 it seems that 1G went to Node0 > Node 1, zone Movable [...] > pages free 448427 > min 3827 > low 4783 > high 5739 > spanned 524288 > present 524288 > managed 515766 and the rest to Node1. Guessing from spanned-managed it seems that used memory is for memmaps (struct page arrays). -- Michal Hocko SUSE Labs
