Re: [PATCH v5 8/8] mm: huge_memory: enable debugfs to split huge pages to any order.

[Ryan Roberts <ryan.roberts@arm.com>]

On 01/03/2024 14:00, Zi Yan wrote:
> On 1 Mar 2024, at 4:51, Aishwarya TCV wrote:
> 
>> On 26/02/2024 20:55, Zi Yan wrote:
>>> From: Zi Yan <ziy@nvidia.com>
>>>
>>> It is used to test split_huge_page_to_list_to_order for pagecache THPs.
>>> Also add test cases for split_huge_page_to_list_to_order via both
>>> debugfs.
>>>
>>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>>> ---
>>>  mm/huge_memory.c                              |  34 ++++--
>>>  .../selftests/mm/split_huge_page_test.c       | 115 +++++++++++++++++-
>>>  2 files changed, 131 insertions(+), 18 deletions(-)
>>>
>>
>> Hi Zi,
>>
>> When booting the kernel against next-master(20240228)with Arm64 on
>> Marvell Thunder X2 (TX2), the kselftest-mm test 'split_huge_page_test'
>> is failing in our CI (with rootfs over NFS). I can send the full logs if
>> required.
>>
>> A bisect (full log below) identified this patch as introducing the
>> failure. Bisected it on the tag "next-20240228" at repo
>> "https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git".
>>
>> This works fine on  Linux version 6.8.0-rc6
> 
> Hi Aishwarya,
> 
> I am trying to fix the issue. When I am compiling selftests/mm, I encountered
> the error below when I run make under the folder. Am I missing any configuration?
> Since you are able to run the test, I assume you know what is happening. Thanks.

for what its worth, I usually compile from the top level directory with:

# make headers_install
# make -C tools/testing/selftests TARGETS=mm install INSTALL_PATH=~/kself

Perhaps the below is due to the headers not being exported properly. Bad things definitely happen if you omit the headers_install step.

> 
> vm_util.c: In function ‘__pagemap_scan_get_categories’:
> vm_util.c:34:28: error: storage size of ‘arg’ isn’t known
>    34 |         struct pm_scan_arg arg;
>       |                            ^~~
> vm_util.c:41:27: error: invalid application of ‘sizeof’ to incomplete type ‘struct pm_scan_arg’
>    41 |         arg.size = sizeof(struct pm_scan_arg);
>       |                           ^~~~~~
> vm_util.c:45:35: error: ‘PAGE_IS_WPALLOWED’ undeclared (first use in this function)
>    45 |         arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE |
>       |                                   ^~~~~~~~~~~~~~~~~
> vm_util.c:45:35: note: each undeclared identifier is reported only once for each function it appears in
> vm_util.c:45:55: error: ‘PAGE_IS_WRITTEN’ undeclared (first use in this function)
>    45 |         arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE |
>       |                                                       ^~~~~~~~~~~~~~~
> vm_util.c:45:73: error: ‘PAGE_IS_FILE’ undeclared (first use in this function)
>    45 |         arg.category_anyof_mask = PAGE_IS_WPALLOWED | PAGE_IS_WRITTEN | PAGE_IS_FILE |
>       |                                                                         ^~~~~~~~~~~~
> vm_util.c:46:35: error: ‘PAGE_IS_PRESENT’ undeclared (first use in this function); did you mean ‘PAGEMAP_PRESENT’?
>    46 |                                   PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |
>       |                                   ^~~~~~~~~~~~~~~
>       |                                   PAGEMAP_PRESENT
> vm_util.c:46:53: error: ‘PAGE_IS_SWAPPED’ undeclared (first use in this function)
>    46 |                                   PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |
>       |                                                     ^~~~~~~~~~~~~~~
> vm_util.c:46:71: error: ‘PAGE_IS_PFNZERO’ undeclared (first use in this function)
>    46 |                                   PAGE_IS_PRESENT | PAGE_IS_SWAPPED | PAGE_IS_PFNZERO |
>       |                                                                       ^~~~~~~~~~~~~~~
> vm_util.c:47:35: error: ‘PAGE_IS_HUGE’ undeclared (first use in this function)
>    47 |                                   PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY;
>       |                                   ^~~~~~~~~~~~
> vm_util.c:47:50: error: ‘PAGE_IS_SOFT_DIRTY’ undeclared (first use in this function); did you mean ‘PM_SOFT_DIRTY’?
>    47 |                                   PAGE_IS_HUGE | PAGE_IS_SOFT_DIRTY;
>       |                                                  ^~~~~~~~~~~~~~~~~~
>       |                                                  PM_SOFT_DIRTY
> vm_util.c:50:26: error: ‘PAGEMAP_SCAN’ undeclared (first use in this function); did you mean ‘PAGEMAP_PFN’?
>    50 |         return ioctl(fd, PAGEMAP_SCAN, &arg);
>       |                          ^~~~~~~~~~~~
>       |                          PAGEMAP_PFN
> 
> --
> Best Regards,
> Yan, Zi