The uffd-wp-mremap test requires the UFFD_FEATURE_PAGEFAULT_FLAG_WP
capability. On systems where userfaultfd write-protect is
not supported, uffd_register() fails and the test reports failures.
Check for the required feature at startup and skip the test when the
UFFD_FEATURE_PAGEFAULT_FLAG_WP capability is not present,
preventing false failures on unsupported configurations.
Before patch:
running ./uffd-wp-mremap
------------------------
[INFO] detected THP size: 256 KiB
[INFO] detected THP size: 512 KiB
[INFO] detected THP size: 1024 KiB
[INFO] detected THP size: 2048 KiB
[INFO] detected hugetlb page size: 2048 KiB
[INFO] detected hugetlb page size: 1048576 KiB
1..24
[RUN] test_one_folio(size=65536, private=false, swapout=false,
hugetlb=false)
not ok 1 uffd_register() failed
[RUN] test_one_folio(size=65536, private=true, swapout=false,
hugetlb=false)
not ok 2 uffd_register() failed
[RUN] test_one_folio(size=65536, private=false, swapout=true,
hugetlb=false)
not ok 3 uffd_register() failed
[RUN] test_one_folio(size=65536, private=true, swapout=true,
hugetlb=false)
not ok 4 uffd_register() failed
[RUN] test_one_folio(size=262144, private=false, swapout=false,
hugetlb=false)
not ok 5 uffd_register() failed
[RUN] test_one_folio(size=524288, private=false, swapout=false,
hugetlb=false)
not ok 6 uffd_register() failed
.
.
.
Bail out! 24 out of 24 tests failed
Totals: pass:0 fail:24 xfail:0 xpass:0 skip:0 error:0
[FAIL]
not ok 1 uffd-wp-mremap # exit=1
After patch:
running ./uffd-wp-mremap
------------------------
1..0 # SKIP uffd-wp feature not supported
[SKIP]
ok 1 uffd-wp-mremap # SKIP
Acked-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
---
tools/testing/selftests/mm/uffd-wp-mremap.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c
index 17186d4a4147..73d53a4da389 100644
--- a/tools/testing/selftests/mm/uffd-wp-mremap.c
+++ b/tools/testing/selftests/mm/uffd-wp-mremap.c
@@ -19,6 +19,17 @@ static size_t thpsizes[20];
static int nr_hugetlbsizes;
static size_t hugetlbsizes[10];
+static void uffd_wp_feature_supported(void)
+{
+ uint64_t features;
+
+ if (uffd_get_features(&features) && errno == ENOENT)
+ ksft_exit_skip("failed to get available features (%d)\n", errno);
+
+ if (!(features & UFFD_FEATURE_PAGEFAULT_FLAG_WP))
+ ksft_exit_skip("uffd-wp feature not supported\n");
+}
+
static int detect_thp_sizes(size_t sizes[], int max)
{
int count = 0;
@@ -336,6 +347,8 @@ int main(int argc, char **argv)
struct thp_settings settings;
int i, j, plan = 0;
+ uffd_wp_feature_supported();
+
pagesize = getpagesize();
nr_thpsizes = detect_thp_sizes(thpsizes, ARRAY_SIZE(thpsizes));
nr_hugetlbsizes = detect_hugetlb_page_sizes(hugetlbsizes,
--
2.52.0On 3/12/26 13:25, Sayali Patil wrote: > The uffd-wp-mremap test requires the UFFD_FEATURE_PAGEFAULT_FLAG_WP > capability. On systems where userfaultfd write-protect is > not supported, uffd_register() fails and the test reports failures. > > Check for the required feature at startup and skip the test when the > UFFD_FEATURE_PAGEFAULT_FLAG_WP capability is not present, > preventing false failures on unsupported configurations. > > Before patch: > running ./uffd-wp-mremap > ------------------------ > [INFO] detected THP size: 256 KiB > [INFO] detected THP size: 512 KiB > [INFO] detected THP size: 1024 KiB > [INFO] detected THP size: 2048 KiB > [INFO] detected hugetlb page size: 2048 KiB > [INFO] detected hugetlb page size: 1048576 KiB > 1..24 > [RUN] test_one_folio(size=65536, private=false, swapout=false, > hugetlb=false) > not ok 1 uffd_register() failed > [RUN] test_one_folio(size=65536, private=true, swapout=false, > hugetlb=false) > not ok 2 uffd_register() failed > [RUN] test_one_folio(size=65536, private=false, swapout=true, > hugetlb=false) > not ok 3 uffd_register() failed > [RUN] test_one_folio(size=65536, private=true, swapout=true, > hugetlb=false) > not ok 4 uffd_register() failed > [RUN] test_one_folio(size=262144, private=false, swapout=false, > hugetlb=false) > not ok 5 uffd_register() failed > [RUN] test_one_folio(size=524288, private=false, swapout=false, > hugetlb=false) > not ok 6 uffd_register() failed > . > . > . > Bail out! 24 out of 24 tests failed > Totals: pass:0 fail:24 xfail:0 xpass:0 skip:0 error:0 > [FAIL] > not ok 1 uffd-wp-mremap # exit=1 > > After patch: > running ./uffd-wp-mremap > ------------------------ > 1..0 # SKIP uffd-wp feature not supported > [SKIP] > ok 1 uffd-wp-mremap # SKIP > > Acked-by: Zi Yan <ziy@nvidia.com> > Signed-off-by: Sayali Patil <sayalip@linux.ibm.com> > --- > tools/testing/selftests/mm/uffd-wp-mremap.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c > index 17186d4a4147..73d53a4da389 100644 > --- a/tools/testing/selftests/mm/uffd-wp-mremap.c > +++ b/tools/testing/selftests/mm/uffd-wp-mremap.c > @@ -19,6 +19,17 @@ static size_t thpsizes[20]; > static int nr_hugetlbsizes; > static size_t hugetlbsizes[10]; > > +static void uffd_wp_feature_supported(void) Likely that function should be called "check_uffd_wp_feature_supported()" Because right now it reads as if it would be returning a bool. Acked-by: David Hildenbrand (Arm) <david@kernel.org> -- Cheers, David
On 12/03/26 18:20, David Hildenbrand (Arm) wrote: > On 3/12/26 13:25, Sayali Patil wrote: >> The uffd-wp-mremap test requires the UFFD_FEATURE_PAGEFAULT_FLAG_WP >> capability. On systems where userfaultfd write-protect is >> not supported, uffd_register() fails and the test reports failures. >> >> Check for the required feature at startup and skip the test when the >> UFFD_FEATURE_PAGEFAULT_FLAG_WP capability is not present, >> preventing false failures on unsupported configurations. >> >> Before patch: >> running ./uffd-wp-mremap >> ------------------------ >> [INFO] detected THP size: 256 KiB >> [INFO] detected THP size: 512 KiB >> [INFO] detected THP size: 1024 KiB >> [INFO] detected THP size: 2048 KiB >> [INFO] detected hugetlb page size: 2048 KiB >> [INFO] detected hugetlb page size: 1048576 KiB >> 1..24 >> [RUN] test_one_folio(size=65536, private=false, swapout=false, >> hugetlb=false) >> not ok 1 uffd_register() failed >> [RUN] test_one_folio(size=65536, private=true, swapout=false, >> hugetlb=false) >> not ok 2 uffd_register() failed >> [RUN] test_one_folio(size=65536, private=false, swapout=true, >> hugetlb=false) >> not ok 3 uffd_register() failed >> [RUN] test_one_folio(size=65536, private=true, swapout=true, >> hugetlb=false) >> not ok 4 uffd_register() failed >> [RUN] test_one_folio(size=262144, private=false, swapout=false, >> hugetlb=false) >> not ok 5 uffd_register() failed >> [RUN] test_one_folio(size=524288, private=false, swapout=false, >> hugetlb=false) >> not ok 6 uffd_register() failed >> . >> . >> . >> Bail out! 24 out of 24 tests failed >> Totals: pass:0 fail:24 xfail:0 xpass:0 skip:0 error:0 >> [FAIL] >> not ok 1 uffd-wp-mremap # exit=1 >> >> After patch: >> running ./uffd-wp-mremap >> ------------------------ >> 1..0 # SKIP uffd-wp feature not supported >> [SKIP] >> ok 1 uffd-wp-mremap # SKIP >> >> Acked-by: Zi Yan <ziy@nvidia.com> >> Signed-off-by: Sayali Patil <sayalip@linux.ibm.com> >> --- >> tools/testing/selftests/mm/uffd-wp-mremap.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/tools/testing/selftests/mm/uffd-wp-mremap.c b/tools/testing/selftests/mm/uffd-wp-mremap.c >> index 17186d4a4147..73d53a4da389 100644 >> --- a/tools/testing/selftests/mm/uffd-wp-mremap.c >> +++ b/tools/testing/selftests/mm/uffd-wp-mremap.c >> @@ -19,6 +19,17 @@ static size_t thpsizes[20]; >> static int nr_hugetlbsizes; >> static size_t hugetlbsizes[10]; >> >> +static void uffd_wp_feature_supported(void) > Likely that function should be called > > "check_uffd_wp_feature_supported()" > > Because right now it reads as if it would be returning a bool. > > Acked-by: David Hildenbrand (Arm) <david@kernel.org> > Thanks for the review. I'll rename it to "check_uffd_wp_feature_supported()" in the next version.
On Fri, 13 Mar 2026 19:56:01 +0530 Sayali Patil <sayalip@linux.ibm.com> wrote:
> >
> > Because right now it reads as if it would be returning a bool.
> >
> > Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> >
> Thanks for the review. I'll rename it to
> "check_uffd_wp_feature_supported()" in the next version.
There was no next version. I added this:
--- a/tools/testing/selftests/mm/uffd-wp-mremap.c~selftests-mm-skip-uffd-wp-mremap-if-uffd-write-protect-is-unsupported-fix
+++ a/tools/testing/selftests/mm/uffd-wp-mremap.c
@@ -19,7 +19,7 @@ static size_t thpsizes[20];
static int nr_hugetlbsizes;
static size_t hugetlbsizes[10];
-static void uffd_wp_feature_supported(void)
+static void check_uffd_wp_feature_supported(void)
{
uint64_t features;
@@ -347,7 +347,7 @@ int main(int argc, char **argv)
struct thp_settings settings;
int i, j, plan = 0;
- uffd_wp_feature_supported();
+ check_uffd_wp_feature_supported();
pagesize = getpagesize();
nr_thpsizes = detect_thp_sizes(thpsizes, ARRAY_SIZE(thpsizes));
_
On 25/03/26 05:26, Andrew Morton wrote:
> On Fri, 13 Mar 2026 19:56:01 +0530 Sayali Patil <sayalip@linux.ibm.com> wrote:
>
>>> Because right now it reads as if it would be returning a bool.
>>>
>>> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
>>>
>> Thanks for the review. I'll rename it to
>> "check_uffd_wp_feature_supported()" in the next version.
> There was no next version. I added this:
>
> --- a/tools/testing/selftests/mm/uffd-wp-mremap.c~selftests-mm-skip-uffd-wp-mremap-if-uffd-write-protect-is-unsupported-fix
> +++ a/tools/testing/selftests/mm/uffd-wp-mremap.c
> @@ -19,7 +19,7 @@ static size_t thpsizes[20];
> static int nr_hugetlbsizes;
> static size_t hugetlbsizes[10];
>
> -static void uffd_wp_feature_supported(void)
> +static void check_uffd_wp_feature_supported(void)
> {
> uint64_t features;
>
> @@ -347,7 +347,7 @@ int main(int argc, char **argv)
> struct thp_settings settings;
> int i, j, plan = 0;
>
> - uffd_wp_feature_supported();
> + check_uffd_wp_feature_supported();
>
> pagesize = getpagesize();
> nr_thpsizes = detect_thp_sizes(thpsizes, ARRAY_SIZE(thpsizes));
> _
>
Hi Andrew,
I have some updates to [PATCH v2 04/13] selftests/mm: fix cgroup task
placement and tolerance in hugetlb_reparenting_test.sh, as Venkat
reported failures with the current version.
Should I send a v3 of the full series, or just a fixup patch for
hugetlb_reparenting_test.sh? Also, if you prefer a v3, should I include
above fix for
selftests-mm-skip-uffd-wp-mremap-if-uffd-write-protect-is-unsupported as
well?
Thanks,
Sayali
On Thu, 26 Mar 2026 23:31:10 +0530 Sayali Patil <sayalip@linux.ibm.com> wrote: > > pagesize = getpagesize(); > > nr_thpsizes = detect_thp_sizes(thpsizes, ARRAY_SIZE(thpsizes)); > > _ > > > Hi Andrew, > I have some updates to [PATCH v2 04/13] selftests/mm: fix cgroup task > placement and tolerance in hugetlb_reparenting_test.sh, as Venkat > reported failures with the current version. > > Should I send a v3 of the full series, or just a fixup patch for > hugetlb_reparenting_test.sh? A full resend is fine, thanks. I'll prepare a diff showing all the changes since v2 for you to double-check and for people who already reviewed v2. > Also, if you prefer a v3, should I include > above fix for > selftests-mm-skip-uffd-wp-mremap-if-uffd-write-protect-is-unsupported as > well? Yes please, integrate all fixups. You may choose to track those fixups the way I do: [avagin@google.com: fix lock leak in mfill_get_vma()] Link: https://lkml.kernel.org/r/20260316173829.1126728-1-avagin@google.com [akpm@linux-foundation.org: update mfill_copy_folio_retry()] Link: https://lkml.kernel.org/r/20260316173829.1126728-1-avagin@google.com Link: https://lkml.kernel.org/r/20260306171815.3160826-6-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Andrei Vagin <avagin@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> ... Other people also do this sometimes, usually not.
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