On 8/6/26 9:25 AM, Zi Yan wrote:
On 5 Aug 2026, at 21:17, Baolin Wang wrote:
On 8/6/26 12:46 AM, Zi Yan wrote:
On Sat Aug 1, 2026 at 2:26 AM EDT, Baolin Wang wrote:
Added a new command 'mthp_khugepaged' for mTHP collapse, along with the '-c'
parameter to specify the collapse order. Additionally, added mTHP collapse
test cases for 'collapse_full', 'collapse_empty', and 'collapse_single_mthp'
for anonymous folios. All khugepaged test cases passed.
Signed-off-by: Baolin Wang <[email protected]>
---
tools/testing/selftests/mm/khugepaged.c | 130 ++++++++++++++++++----
tools/testing/selftests/mm/run_vmtests.sh | 2 +
2 files changed, 113 insertions(+), 19 deletions(-)
diff --git a/tools/testing/selftests/mm/khugepaged.c
b/tools/testing/selftests/mm/khugepaged.c
index f69be6be0ecd..64d6da6aa90d 100644
--- a/tools/testing/selftests/mm/khugepaged.c
+++ b/tools/testing/selftests/mm/khugepaged.c
@@ -26,9 +26,11 @@
#define BASE_ADDR ((void *)(1UL << 30))
static unsigned long hpage_pmd_size;
+static int hpage_pmd_order;
static unsigned long page_size;
static int hpage_pmd_nr;
static int anon_order;
+static int collapse_order;
<snip>
diff --git a/tools/testing/selftests/mm/run_vmtests.sh
b/tools/testing/selftests/mm/run_vmtests.sh
index 687d115e3bd8..d09f9f6a384e 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -410,6 +410,8 @@ CATEGORY="thp" run_test ./khugepaged all:shmem
CATEGORY="thp" run_test ./khugepaged -s 4 all:shmem
+CATEGORY="thp" run_test ./khugepaged -c 4 mthp_khugepaged:anon
Why only testing collapse_order == 4? It is more useful to test all
possible mTHP orders. -c can accept common separated order and a range.
This also follows the previous '-s' parameter configuration, which is used to
specify the mTHP order allocation.
I think specifying a single order size already tests the overall mTHP collapse
Got it. If a single order covers the flow, I am fine with it.
flow, so I'm not sure whether testing all orders is worthwhile. Maybe I can add
a few more orders?
./khugepaged -c 2 mthp_khugepaged:anon
./khugepaged -c 4 mthp_khugepaged:anon
./khugepaged -c 8 mthp_khugepaged:anon
Why only testing mthp_khugepaged:anon? IIRC, file and shmem are not
supported, so khugepaged should reject them, right?
Currently, I have not added test cases for shmem mTHP collapse, so adding file
or shmem would be no-ops and might mislead others. I will add the shmem/file
mTHP collapse feature and test cases in a following patchset.
Right. I mean when one specifies ./khugepaged mthp_khugepaged:file/shmem, the
program should show some error like “file/shmem not supported”.
Yes, that works too. I still prefer to add the corresponding test cases
after I add shmem mTHP collapse support:)
But if you have a strong opinion on this, I can also add a "not
supported" message first.
