[RFC,lsfmm,0/6] mm: proactive reclaim and memory tiering topics

Message

Davidlohr Bueso April 16, 2022, 5:38 a.m. UTC

Hello,

With the increasing popularity of memory tiering, the idea of this series is to trigger
some discussion around David's[1] system-wide proactive reclaim beyond memcg[2] as well
as sysfs as the interface for exporting system-wide tiering information[2]. I am
hoping this can be discussed at LSFMM, and while I know many are interested in tiering
subjects in general, I have not seen anyone bring this up in the list.

There has been some initial discussion towards the need to expose system-wide tiering
information to userspace. I thought I'd start with two sysfs files as a node attribute
that exports the demotion_node as well as whether or not the node is fast memory. This
was considered (and I agree) better than a new /sys/devices/system/tier/tierN/ interface.
So, are we going to go this route? If so, what further information is useful for users?
Does having instead a /sys/devices/system/node/nodeN/reclaim/ make sense?
  
Applies against Linus' current tree and has only been _gently_ tested.

Thanks!

Davidlohr Bueso (6):
  drivers/base/node: cleanup register_node()
  mm/vmscan: use node_is_toptier helper in node_reclaim
  mm: make __node_reclaim() more flexible
  mm: introduce per-node proactive reclaim interface
  mm/migration: export demotion_path of a node via sysfs
  mm/migrate: export whether or not tier is toptier in sysfs

 Documentation/ABI/stable/sysfs-devices-node |  22 ++++
 drivers/base/node.c                         |  68 ++++++++++--
 include/linux/migrate.h                     |  15 +++
 include/linux/swap.h                        |  16 +++
 include/trace/events/vmscan.h               |  12 +--
 mm/migrate.c                                |  15 +--
 mm/vmscan.c                                 | 108 +++++++++++++++-----
 7 files changed, 206 insertions(+), 50 deletions(-)

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2.26.2