Messages in this thread | | | Subject | Re: [PATCH] mm: don't rely on system state to detect hot-plug operations | From | Laurent Dufour <> | Date | Thu, 10 Sep 2020 14:32:02 +0200 |
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Le 10/09/2020 à 14:03, Oscar Salvador a écrit : > On Thu, Sep 10, 2020 at 01:35:32PM +0200, Laurent Dufour wrote: > >> That points has been raised by David, quoting him here: >> >>> IIRC, ACPI can hotadd memory while SCHEDULING, this patch would break that. >>> >>> Ccing Oscar, I think he mentioned recently that this is the case with ACPI. >> >> Oscar told that he need to investigate further on that. > > I think my reply got lost. > > We can see acpi hotplugs during SYSTEM_SCHEDULING: > > $QEMU -enable-kvm -machine pc -smp 4,sockets=4,cores=1,threads=1 -cpu host -monitor pty \ > -m size=$MEM,slots=255,maxmem=4294967296k \ > -numa node,nodeid=0,cpus=0-3,mem=512 -numa node,nodeid=1,mem=512 \ > -object memory-backend-ram,id=memdimm0,size=134217728 -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ > -object memory-backend-ram,id=memdimm1,size=134217728 -device pc-dimm,node=0,memdev=memdimm1,id=dimm1,slot=1 \ > -object memory-backend-ram,id=memdimm2,size=134217728 -device pc-dimm,node=0,memdev=memdimm2,id=dimm2,slot=2 \ > -object memory-backend-ram,id=memdimm3,size=134217728 -device pc-dimm,node=0,memdev=memdimm3,id=dimm3,slot=3 \ > -object memory-backend-ram,id=memdimm4,size=134217728 -device pc-dimm,node=1,memdev=memdimm4,id=dimm4,slot=4 \ > -object memory-backend-ram,id=memdimm5,size=134217728 -device pc-dimm,node=1,memdev=memdimm5,id=dimm5,slot=5 \ > -object memory-backend-ram,id=memdimm6,size=134217728 -device pc-dimm,node=1,memdev=memdimm6,id=dimm6,slot=6 \ > > kernel: [ 0.753643] __add_memory: nid: 0 start: 0100000000 - 0108000000 (size: 134217728) > kernel: [ 0.756950] register_mem_sect_under_node: system_state= 1 > > kernel: [ 0.760811] register_mem_sect_under_node+0x4f/0x230 > kernel: [ 0.760811] walk_memory_blocks+0x80/0xc0 > kernel: [ 0.760811] link_mem_sections+0x32/0x40 > kernel: [ 0.760811] add_memory_resource+0x148/0x250 > kernel: [ 0.760811] __add_memory+0x5b/0x90 > kernel: [ 0.760811] acpi_memory_device_add+0x130/0x300 > kernel: [ 0.760811] acpi_bus_attach+0x13c/0x1c0 > kernel: [ 0.760811] acpi_bus_attach+0x60/0x1c0 > kernel: [ 0.760811] acpi_bus_scan+0x33/0x70 > kernel: [ 0.760811] acpi_scan_init+0xea/0x21b > kernel: [ 0.760811] acpi_init+0x2f1/0x33c > kernel: [ 0.760811] do_one_initcall+0x46/0x1f4
Thanks Oscar!
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