docs: mm: add enable_soft_offline sysctl

Add the documentation for soft offline behaviors / costs, and what the new
enable_soft_offline sysctl is for.

[[email protected]: fix kerneldoc warnings]
  Link: https://lkml.kernel.org/r/CACw3F52=GxTCDw-PqFh3-GDM-fo3GbhGdu0hedxYXOTT4TQSTg@mail.gmail.com
[[email protected]: there are more blank lines needed]
  Link: https://lkml.kernel.org/r/CACw3F52_obAB742XeDRNun4BHBYtrxtbvp5NkUincXdaob0j1g@mail.gmail.com
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Jiaqi Yan <[email protected]>
Acked-by: Oscar Salvador <[email protected]>
Acked-by: Miaohe Lin <[email protected]>
Acked-by: David Rientjes <[email protected]>
Cc: Frank van der Linden <[email protected]>
Cc: Jane Chu <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: Shuah Khan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions