Re: [PATCH -v2 0/9] mm: make movable onlining suck less

[Michal Hocko]

On Tue 11-04-17 11:59:31, Igor Mammedov wrote:
> On Tue, 11 Apr 2017 11:23:07 +0200
> Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> 
> > On Tue 11-04-17 08:38:34, Igor Mammedov wrote:
> > > for issue2:
> > > -enable-kvm -m 2G,slots=4,maxmem=4G -smp 4 -numa node -numa node \
> > > -drive if=virtio,file=disk.img -kernel bzImage -append 'root=/dev/vda1' \
> > > -object memory-backend-ram,id=mem1,size=256M -object memory-backend-ram,id=mem0,size=256M \
> > > -device pc-dimm,id=dimm1,memdev=mem1,slot=1,node=0 -device pc-dimm,id=dimm0,memdev=mem0,slot=0,node=1  
> > 
> > I must be doing something wrong here...
> > qemu-system-x86_64 -enable-kvm -monitor telnet:127.0.0.1:9999,server,nowait -net nic -net user,hostfwd=tcp:127.0.0.1:5555-:22 -serial file:test.qcow_serial.log -enable-kvm -m 2G,slots=4,maxmem=4G -smp 4 -numa node -numa node -object memory-backend-ram,id=mem1,size=256M -object memory-backend-ram,id=mem0,size=256M -device pc-dimm,id=dimm1,memdev=mem1,slot=1,node=0 -device pc-dimm,id=dimm0,memdev=mem0,slot=0,node=1 -drive file=test.qcow,if=ide,index=0
> > 
> > for i in $(seq 0 3)
> > do
> > 	sh probe_memblock.sh $i
> > done
>
> dimm to node mapping comes from ACPI subsystem (_PXM object in memory device),
> which adds memory blocks automatically on hotplug.

Hmm, memory_probe_store relies on memory_add_physaddr_to_nid which in
turn relies on numa_meminfo. I am not familiar with the intialization
and got lost in in the code rather quickly but I assumed this should get
the proper information from the ACPI subsystem. I will have to double
check.

> you probably don't have ACPI_HOTPLUG_MEMORY config option enabled.

Yes that is the case and enabling it made all 4 memblocks available
and associated with the proper node
# ls -l /sys/devices/system/memory/memory3?/node*
lrwxrwxrwx 1 root root 0 Apr 11 12:56 /sys/devices/system/memory/memory32/node0 -> ../../node/node0
lrwxrwxrwx 1 root root 0 Apr 11 12:56 /sys/devices/system/memory/memory33/node0 -> ../../node/node0
lrwxrwxrwx 1 root root 0 Apr 11 12:56 /sys/devices/system/memory/memory34/node1 -> ../../node/node1
lrwxrwxrwx 1 root root 0 Apr 11 12:56 /sys/devices/system/memory/memory35/node1 -> ../../node/node1

# grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
/sys/devices/system/memory/memory35/valid_zones:Normal Movable

I can even reproduce your problem
# echo online_movable > /sys/devices/system/memory/memory33/state
# echo online > /sys/devices/system/memory/memory32/state
# grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Movable
/sys/devices/system/memory/memory33/valid_zones:Movable
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
/sys/devices/system/memory/memory35/valid_zones:Normal Movable

I will investigate this
-- 
Michal Hocko
SUSE Labs