Re: [Qemu-devel] [RFC] memory consumption of Qemu is twice as much as the previous version in KVM

[Paolo Bonzini]

On 22/05/2017 17:11, Gonglei (Arei) wrote:
>> These are kernel allocations done by KVM when it gets the
>> KVM_SET_USER_MEMORY_REGION ioctl; of course the two memory maps
>> point to
>> the same userspace mmap-ed area.
>
> Oh? What's the mmapd-ed area you pointed?

I mean the MAP_ANON pages that back the guest memory.

> If the KVM allocate memory by vmalloc(), then it will occupy physical
> memory (non physically contiguous memory) IMO.
> 
> We can get the information from /proc/meminfo:
> 
> # cat /proc/meminfo |grep Vmalloc     
> VmallocTotal:   34359738367 kB
> VmallocUsed:      532796 kB
> VmallocChunk:   34292018200 kB
> 
> So I think this part of memory is double after that SMM commit. Right?

Yes.

Paolo