mm/page_reporting: add page_reporting_delay_ms module parameter

Free page reporting currently hardcodes a 2-second interval between
reports.  This rigid delay cannot accommodate diverse guest workloads.

This patch introduces a module parameter, page_reporting_delay_ms
(default: 2000), allowing users to tune the reporting rate:
 - Lower values enable aggressive memory reclamation by returning unused
   pages to the host immediately.
 - Higher values help batch pages during spiky allocation/free churn,
   reducing hypercalls and nested page fault overheads.

Setting the delay to 0 is safe and execution is strictly gated by:
 - reporting is only triggered by high-order page frees.
 - expensive hypercalls are bounded by a slot capacity watermark check
   before proceeding.

Link: https://lore.kernel.org/20260731193705.2902728-1-pratmal@google.com
Signed-off-by: Pratyush Mallick <pratmal@google.com>
Reviewed-by: SJ Park <sj@kernel.org>
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions