[PATCH v6 5/6] mm: secretmem: use PMD-size pages to amortize direct map fragmentation

[Peter Zijlstra]

On Wed, Sep 30, 2020 at 01:20:31PM +0300, Mike Rapoport wrote:

> I tried to dig the regression report in the mailing list, and the best I
> could find is
> 
> https://lore.kernel.org/lkml/20190823052335.572133-1-songliubraving@fb.com/
> 
> which does not mention the actual performance regression but it only
> complaints about kernel text mapping being split into 4K pages.
> 
> Any chance you have the regression report handy? 

I think the saga started here:

 20190820075128.2912224-1-songliubraving at fb.com
 20190820202314.1083149-1-songliubraving at fb.com
 20190823052335.572133-1-songliubraving at fb.com

After that Thomas did the patch I referred to earlier and I endeavoured
to rewrite x86-ftrace.

I added Song to CC, maybe he can remember more.