Re: [PATCH v2 1/2] mm: disable LRU pagevec during the migration temporarily

[Minchan Kim <minchan@kernel.org>]

On Tue, Mar 09, 2021 at 05:31:09PM +0100, David Hildenbrand wrote:
> 
> > > > Signed-off-by: Minchan Kim <minchan@kernel.org>
> > > > ---
> > > > * from v1 - https://lore.kernel.org/lkml/20210302210949.2440120-1-minchan@kernel.org/
> > > >    * introduce __lru_add_drain_all to minimize changes - mhocko
> > > >    * use lru_cache_disable for memory-hotplug
> > > >    * schedule for every cpu at force_all_cpus
> > > > 
> > > > * from RFC - http://lore.kernel.org/linux-mm/20210216170348.1513483-1-minchan@kernel.org
> > > >    * use atomic and lru_add_drain_all for strict ordering - mhocko
> > > >    * lru_cache_disable/enable - mhocko
> > > > 
> > > >   include/linux/migrate.h |  6 ++-
> > > >   include/linux/swap.h    |  2 +
> > > >   mm/memory_hotplug.c     |  3 +-
> > > >   mm/mempolicy.c          |  6 +++
> > > >   mm/migrate.c            | 13 ++++---
> > > >   mm/page_alloc.c         |  3 ++
> > > >   mm/swap.c               | 82 +++++++++++++++++++++++++++++++++--------
> > > >   7 files changed, 91 insertions(+), 24 deletions(-)
> > > 
> > > Sorry for nit picking but I think the additional abstraction for
> > > migrate_prep is not really needed and we can remove some more code.
> > > Maybe we should even get rid of migrate_prep_local which only has a
> > > single caller and open coding lru draining with a comment would be
> > > better from code reading POV IMO.
> > 
> > Thanks for the code. I agree with you.
> > However, in this moment, let's go with this one until we conclude.
> > The removal of migrate_prep could be easily done after that.
> > I am happy to work on it.
> 
> Can you prepare + send along these cleanups so we can have a look at the end
> result?
> 
> (either cleanups before or after your changes - doing cleanups before might
> be cleaner as we are not dealing with a fix here that we want to backport)

Okay, let me try one more time.