On 5 Aug 2026, at 21:30, Baolin Wang wrote: > 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:)
Sure. Or update usage() to print “mthp_khugepaged only supports anon”. You can remove that after you add other support types. > > But if you have a strong opinion on this, I can also add a "not supported" > message first. Best Regards, Yan, Zi
