On 03.04.25 12:38, Pankaj Raghav (Samsung) wrote:
From: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
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@xxxxxxxxxxx>
---
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``.
+
These changed look good. Do we also want to talk about FilePmdMapped?
(PMD-sized THPs in the page cache that are mapped in to user space using
a PMD ?)
Do we have to distinguish it from below? (shmem also uses the page cache)
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
Previously here, but: this reads rather odd. "file transparent huge
pages". "PMD-sized THPs specific to shmem are tracked separately ..." ?
--
Cheers,
David / dhildenb
