Re: [RFC PATCH 00/16] 1GB THP support on x86_64

[Jason Gunthorpe]

On Wed, Sep 09, 2020 at 01:32:44PM +0100, Matthew Wilcox wrote:

> But here's the thing ... we already allow
> 	mmap(MAP_POPULATE | MAP_HUGETLB | MAP_HUGE_1GB)
> 
> So if we're not doing THP, what's the point of this thread?

I wondered that too..

> An madvise flag is a different beast; that's just letting the kernel
> know what the app thinks its behaviour will be.  The kernel can pay

But madvise is too late, the VMA already has an address, if it is not
1G aligned it cannot be 1G THP already.

Jason