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”. Best Regards, Yan, Zi
