[PATCH 0/3] [v2] Repair and clean up vm.zone_reclaim_mode sysctl ABI

[Dave Hansen <dave.hansen@linux.intel.com>]

A previous cleanup accidentally changed the vm.zone_reclaim_mode ABI.

This series restores the ABI and then reorganizes the code to make
the ABI more obvious.  Since the single-patch v1[1], I've:

 * Restored the RECLAIM_ZONE naming, comment and Documentation now
   that the implicit checks for it are known.
 * Move RECLAIM_* definitions to a uapi header
 * Add a node_reclaim_enabled() helper

 Documentation/admin-guide/sysctl/vm.rst |   10 +++++-----
 include/linux/swap.h                    |    7 +++++++
 include/uapi/linux/mempolicy.h          |    7 +++++++
 mm/khugepaged.c                         |    2 +-
 mm/page_alloc.c                         |    2 +-
 mm/vmscan.c                             |    3 ---
 6 files changed, 21 insertions(+), 10 deletions(-)

1. https://lore.kernel.org/linux-mm/20200626003459.D8E015CA@viggo.jf.intel.com/

Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Daniel Wagner <dwagner@suse.de>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Daniel Wagner <dwagner@suse.de>