[PATCH v2 1/2] docs: update THP admin guide about non-tmpfs filesystem support

["Pankaj Raghav (Samsung)" <kernel@pankajraghav.com>]

From: Pankaj Raghav <p.raghav@samsung.com>

THP support for non-tmpfs filesystem has been around for some time now.
Update the admin guide to reflect it.

Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 Documentation/admin-guide/mm/transhuge.rst | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index dff8d5985f0f..01b7ce90d693 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -12,8 +12,8 @@ using huge pages for the backing of virtual memory with huge pages
 that supports the automatic promotion and demotion of page sizes and
 without the shortcomings of hugetlbfs.
 
-Currently THP only works for anonymous memory mappings and tmpfs/shmem.
-But in the future it can expand to other filesystems.
+Currently, THP only works for anonymous memory mappings, tmpfs/shmem and
+filesystems that support large folios.
 
 .. note::
    in the examples below we presume that the basic page size is 4K and
@@ -463,6 +463,10 @@ fields for each mapping. (Note that AnonHugePages only applies to traditional
 PMD-sized THP for historical reasons and should have been called
 AnonHugePmdMapped).
 
+The number of PMD-sized transparent huge pages currently used by
+filesystem data (page cache) is available by reading the FileHugePages field
+in ``/proc/meminfo``.
+
 The number of file transparent huge pages mapped to userspace is available
 by reading ShmemPmdMapped and ShmemHugePages fields in ``/proc/meminfo``.
 To identify what applications are mapping file transparent huge pages, it
-- 
2.47.2