Re: [RFC] mm: why vfree() do not free page table memory?

[Matthew Wilcox]

On Wed, Jan 17, 2018 at 05:48:57PM +0800, Xishi Qiu wrote:
> > Did you notice an actual issue, or is this just theoretical concern.
> 
> Yes, we have this problem on our production line.
> I find the page table memory takes 200-300M.

200MB?  That's mapping 800GB of virtual address space.  That must be
quite the module you're loading there ...