On Tue, Jun 16, 2020 at 5:51 AM Michal Hocko <mho...@kernel.org> wrote:
>
> On Tue 16-06-20 13:52:12, David Hildenbrand wrote:
> > Commit e900a918b098 ("mm: shuffle initial free memory to improve
> > memory-side-cache utilization") introduced shuffling of free pages
> > during system boot and whenever we online memory blocks.
> >
> > However, whenever we online memory blocks, all pages that will be
> > exposed to the buddy end up getting freed via __free_one_page(). In the
> > general case, we free these pages in MAX_ORDER - 1 chunks, which
> > corresponds to the shuffle order.
> >
> > Inside __free_one_page(), we will already shuffle the newly onlined pages
> > using "to_tail = shuffle_pick_tail();". Drop explicit zone shuffling on
> > memory hotplug.
> >
> > Note: When hotplugging a DIMM, each memory block (e.g., 128MB .. 2G on
> > x86-64) will get onlined individually, resulting in a shuffle_zone() for
> > every memory block getting onlined.
> >
> > Cc: Andrew Morton <a...@linux-foundation.org>
> > Cc: Alexander Duyck <alexander.h.du...@linux.intel.com>
> > Cc: Dan Williams <dan.j.willi...@intel.com>
> > Cc: Michal Hocko <mho...@suse.com>
> > Cc: Dave Hansen <dave.han...@linux.intel.com>
> > Cc: Kees Cook <keesc...@chromium.org>
> > Cc: Mel Gorman <mgor...@techsingularity.net>
> > Signed-off-by: David Hildenbrand <da...@redhat.com>
>
> Acked-by: Michal Hocko <mho...@suse.com>Nacked-by: Dan Williams <dan.j.willi...@intel.com> As explained in another thread this is in active use.
