ACK: [SRU][D / B aws-edge][aws][PULL] proper hibernation support

[Andrea Righi]

On Thu, Jan 16, 2020 at 03:37:12PM +0000, Colin Ian King wrote:
> On 16/01/2020 14:34, Andrea Righi wrote:
> > BugLink: https://bugs.launchpad.net/bugs/1858618
> > BugLink: https://bugs.launchpad.net/bugs/1831940
> > 
> > The following patches are required to properly support hibernation with
> > bionic:linux-aws-edge / disco:linux-aws.
> > 
> > The most important patch is "PM / hibernate: memory_bm_find_bit():
> > Tighten node optimisation": this is a very critical bug fix for
> > hibernation that prevents potential memory corruptions on resume.
> > 
> > The two SAUCE patches are required to improve swapoff performance after
> > a successful resume.
> > 
> > All these patches have been tested in the AWS environment with positive
> > results.
> > 
> > The following changes since commit 0f84693e79c7c596ac56d952851e0b9527679689:
> > 
> >   UBUNTU: Ubuntu-aws-edge-5.0.0-1019.21~18.04.1 (2019-10-03 00:49:16 -0400)
> > 
> > are available in the Git repository at:
> > 
> >   git://git.launchpad.net/~arighi/+git/bionic-linux aws-edge-arighi
> > 
> > for you to fetch changes up to 65f789bf0216b2daf6377c2ba51d94cb8b76e5e1:
> > 
> >   UBUNTU SAUCE [aws]: mm: swap: improve swap readahead heuristic (2020-01-16 15:19:46 +0100)
> > 
> > ----------------------------------------------------------------
> > Andrea Righi (2):
> >       UBUNTU SAUCE [aws] PM / hibernate: reduce memory pressure during image writing
> >       UBUNTU SAUCE [aws]: mm: swap: improve swap readahead heuristic
> > 
> > Andy Whitcroft (1):
> >       PM / hibernate: memory_bm_find_bit(): Tighten node optimisation
> > 
> > Vineeth Remanan Pillai (2):
> >       mm: refactor swap-in logic out of shmem_getpage_gfp
> >       mm: rid swapoff of quadratic complexity
> > 
> >  include/linux/frontswap.h |   7 +
> >  include/linux/shmem_fs.h  |   3 +-
> >  kernel/power/snapshot.c   |   9 +-
> >  kernel/power/swap.c       |  24 +-
> >  mm/shmem.c                | 716 +++++++++++++++++++++++++---------------------
> >  mm/swap.c                 |   2 +-
> >  mm/swap_state.c           |  60 +---
> >  mm/swapfile.c             | 433 +++++++++++-----------------
> >  8 files changed, 582 insertions(+), 672 deletions(-)
> > 
> 
> I'm happy with these changes. Are any of these sauce patches upstream
> material?

I'm working on making the swapoff optimization more suitable for
upstream. In particular, this should be a sysfs tunable (at least),
because optimizing swapoff at the cost of slowing down the entire system
can be really bad in many cases, but there are cases like this where you
may really want swapoff to complete as fast as possible.

Thanks,
-Andrea