Messages in this thread | | | Date | Tue, 12 Feb 2019 15:42:42 +0100 | From | Michal Hocko <> | Subject | Re: [RFC PATCH v2 0/4] mm, memory_hotplug: allocate memmap from hotadded memory |
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On Tue 12-02-19 14:56:58, Oscar Salvador wrote: > On Tue, Feb 12, 2019 at 01:21:38PM +0000, Shameerali Kolothum Thodi wrote: > > > Hi Oscar, > > > > > > I ran tests on one of our arm64 machines. Particular machine doesn't actually > > > have > > > the mechanics for hotplug, so was all 'faked', but software wise it's all the > > > same. > > > > > > Upshot, seems to work as expected on arm64 as well. > > > Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Thanks Jonathan for having given it a spin, much appreciated! > I was short of arm64 machines. > > > (qemu) object_add memory-backend-ram,id=mem1,size=1G > > (qemu) device_add pc-dimm,id=dimm1,memdev=mem1,node=1 > > root@ubuntu:~# > > root@ubuntu:~# numactl -H > ... > > node 1 cpus: > > node 1 size: 1008 MB > > node 1 free: 1008 MB > > node distances: > > node 0 1 > > 0: 10 20 > > 1: 20 10 > > root@ubuntu:~# > > Ok, this is what I wanted to see. > When you hotplugged 1GB, 16MB out of 1024MB were spent > for the memmap array, that is why you only see 1008MB there. > > I am not sure what is the default section size for arm64, but assuming > is 128MB, that would make sense as 1GB would mean 8 sections, > and each section takes 2MB. > > That means that at least the mechanism works.
Please make sure to test on a larger machine which has multi section memblocks. This is where I was hitting on bugs hard. -- Michal Hocko SUSE Labs
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