Re: [RFC PATCH] mm: align anon mmap for THP

[Michal Hocko]

On Mon 14-01-19 16:54:02, Harrosh, Boaz wrote:
> Michal Hocko <mhocko@xxxxxxxxxx> wrote:
[...]
> >> We run with our own compiled Kernel on various distros, THP is configured
> >> in but mmap against /dev/shm/ never gives me Huge pages. Does it only
> >> work with unanimous mmap ? (I think it is mount dependent which is not
> >> in the application control)
> >
> > If you are talking about THP then you have to enable huge pages for the
> > mapping AFAIR.
> 
> This is exactly what I was looking to achieve but was not able to do. Most probably
> a stupid omission on my part, but just to show that it is not that trivial and strait
> out-of-the-man-page way to do it.  (Would love a code snippet if you ever wrote one?)

Have you tried
mount -t tmpfs -o huge=always none $MNT_POINT ?

It is true that man pages are silent about this but at least Documentation/admin-guide/mm/transhuge.rst
has an information. Time to send a patch to man pages I would say.
-- 
Michal Hocko
SUSE Labs