Re: [PATCH v2 1/1] mm/madvise: add MADV_F_COLLAPSE_LIGHT to process_madvise()

[Lance Yang <ioworker0@xxxxxxxxx>]

On Fri, Jan 26, 2024 at 6:15 PM Lance Yang <ioworker0@xxxxxxxxx> wrote:
[...]
> > If the kernel supports a more relaxed (opportunistic)
> > MADV_COLLAPSE, we will modify the THP settings as follows:
> >
> > echo madvise >/sys/kernel/mm/transparent_hugepage/enabled
> > echo madvise >/sys/kernel/mm/transparent_hugepage/defrag
>
> The correct THP settings should be:
> echo always >/sys/kernel/mm/transparent_hugepage/enabled
> echo madvise >/sys/kernel/mm/transparent_hugepage/defrag
>

Apologize for the confusion in my previous email.

The third type of requirements prefers not to use huge pages at all.
The correct THP settings should be:
echo madvise >/sys/kernel/mm/transparent_hugepage/enabled
echo defer+madvise >/sys/kernel/mm/transparent_hugepage/defrag

> >
> > Then, we will use process_madvise(MADV_COLLAPSE, xx_relaxed_flag)
> > to address the requirements of the second type.
[...]