The quilt patch titled
Subject: mm: add docs for per-order mTHP counters and transhuge_page ABI
has been removed from the -mm tree. Its filename was
mm-add-docs-for-per-order-mthp-counters-and-transhuge_page-abi.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Barry Song <v-songbaohua@xxxxxxxx>
Subject: mm: add docs for per-order mTHP counters and transhuge_page ABI
Date: Fri, 12 Apr 2024 23:48:57 +1200
This patch includes documentation for mTHP counters and an ABI file for
sys-kernel-mm-transparent-hugepage, which appears to have been missing for
some time.
[v-songbaohua@xxxxxxxx: fix the name and unexpected indentation]
Link: https://lkml.kernel.org/r/20240415054538.17071-1-21cnbao@xxxxxxxxx
Link: https://lkml.kernel.org/r/20240412114858.407208-4-21cnbao@xxxxxxxxx
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: Domenico Cerasuolo <cerasuolodomenico@xxxxxxxxx>
Cc: Kairui Song <kasong@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-kernel-mm-transparent-hugepage | 18 ++++++
Documentation/admin-guide/mm/transhuge.rst | 28 ++++++++++
2 files changed, 46 insertions(+)
--- /dev/null
+++ a/Documentation/ABI/testing/sysfs-kernel-mm-transparent-hugepage
@@ -0,0 +1,18 @@
+What: /sys/kernel/mm/transparent_hugepage/
+Date: April 2024
+Contact: Linux memory management mailing list <linux-mm@xxxxxxxxx>
+Description:
+ /sys/kernel/mm/transparent_hugepage/ contains a number of files and
+ subdirectories,
+
+ - defrag
+ - enabled
+ - hpage_pmd_size
+ - khugepaged
+ - shmem_enabled
+ - use_zero_page
+ - subdirectories of the form hugepages-<size>kB, where <size>
+ is the page size of the hugepages supported by the kernel/CPU
+ combination.
+
+ See Documentation/admin-guide/mm/transhuge.rst for details.
--- a/Documentation/admin-guide/mm/transhuge.rst~mm-add-docs-for-per-order-mthp-counters-and-transhuge_page-abi
+++ a/Documentation/admin-guide/mm/transhuge.rst
@@ -447,6 +447,34 @@ thp_swpout_fallback
Usually because failed to allocate some continuous swap space
for the huge page.
+In /sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/stats, There are
+also individual counters for each huge page size, which can be utilized to
+monitor the system's effectiveness in providing huge pages for usage. Each
+counter has its own corresponding file.
+
+anon_fault_alloc
+ is incremented every time a huge page is successfully
+ allocated and charged to handle a page fault.
+
+anon_fault_fallback
+ is incremented if a page fault fails to allocate or charge
+ a huge page and instead falls back to using huge pages with
+ lower orders or small pages.
+
+anon_fault_fallback_charge
+ is incremented if a page fault fails to charge a huge page and
+ instead falls back to using huge pages with lower orders or
+ small pages even though the allocation was successful.
+
+anon_swpout
+ is incremented every time a huge page is swapped out in one
+ piece without splitting.
+
+anon_swpout_fallback
+ is incremented if a huge page has to be split before swapout.
+ Usually because failed to allocate some continuous swap space
+ for the huge page.
+
As the system ages, allocating huge pages may be expensive as the
system uses memory compaction to copy data around memory to free a
huge page for use. There are some counters in ``/proc/vmstat`` to help
_
Patches currently in -mm which might be from v-songbaohua@xxxxxxxx are
