Re: [PATCH 3/4] mm: add shared read-only vmemmap support for FS-DAX

[Yilei Zheng]

I forgot to mention the tool execution case in my last mail. Those
microVMs start, run a small task, and exit. DAX is there to save
memory, but the vmemmap is allocated for the whole image. A 2 GiB
image pays 32 MiB of vmemmap even if a microVM only reads a few MB, so
for those microVMs the DAX setup can use more memory than the same
image on virtio-blk. That is also a case this series fixes for us.