| Message ID | 20230717103152.202078-3-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f6dd4e223d8798319d0e2815a468b9fb0a276446 |
| Headers | show |
| Series | selftests/mm fixes for arm64 | expand |
On 17.07.23 12:31, Ryan Roberts wrote: > arm64 does not support the soft-dirty PTE bit. However, the `soft-dirty` > test suite is currently run unconditionally and therefore generates > spurious test failures on arm64. There are also some tests in > `madv_populate` which assume it is supported. > > For `soft-dirty` lets disable the whole suite for arm64; it is no longer > built and run_vmtests.sh will skip it if its not present. > > For `madv_populate`, we need a runtime mechanism so that the remaining > tests continue to be run. Unfortunately, the only way to determine if > the soft-dirty dirty bit is supported is to write to a page, then see if > the bit is set in /proc/self/pagemap. But the tests that we want to > conditionally execute are testing precicesly this. So if we introduced > this feature check, we could accedentally turn a real failure (on a > system that claims to support soft-dirty) into a skip. So instead, do > the check based on architecture; for arm64, we report that soft-dirty is > not supported. > > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > tools/testing/selftests/mm/Makefile | 5 ++++- > tools/testing/selftests/mm/madv_populate.c | 26 ++++++++++++++++++++-- > tools/testing/selftests/mm/run_vmtests.sh | 5 ++++- > 3 files changed, 32 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile > index 66d7c07dc177..3514697fc2db 100644 > --- a/tools/testing/selftests/mm/Makefile > +++ b/tools/testing/selftests/mm/Makefile > @@ -63,12 +63,15 @@ TEST_GEN_PROGS += thuge-gen > TEST_GEN_PROGS += transhuge-stress > TEST_GEN_PROGS += uffd-stress > TEST_GEN_PROGS += uffd-unit-tests > -TEST_GEN_PROGS += soft-dirty > TEST_GEN_PROGS += split_huge_page_test > TEST_GEN_PROGS += ksm_tests > TEST_GEN_PROGS += ksm_functional_tests > TEST_GEN_PROGS += mdwe_test > > +ifneq ($(ARCH),arm64) > +TEST_GEN_PROGS += soft-dirty > +endif > + > ifeq ($(ARCH),x86_64) > CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_32bit_program.c -m32) > CAN_BUILD_X86_64 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_64bit_program.c) > diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c > index 60547245e479..17bcb07f19f3 100644 > --- a/tools/testing/selftests/mm/madv_populate.c > +++ b/tools/testing/selftests/mm/madv_populate.c > @@ -264,14 +264,35 @@ static void test_softdirty(void) > munmap(addr, SIZE); > } > > +static int system_has_softdirty(void) > +{ > + /* > + * There is no way to check if the kernel supports soft-dirty, other > + * than by writing to a page and seeing if the bit was set. But the > + * tests are intended to check that the bit gets set when it should, so > + * doing that check would turn a potentially legitimate fail into a > + * skip. Fortunately, we know for sure that arm64 does not support > + * soft-dirty. So for now, let's just use the arch as a corse guide. > + */ > +#if defined(__aarch64__) > + return 0; > +#else > + return 1; > +#endif > +} I guess that will also make the compiler remove any traces of test_softdirty()( from the binary. Acked-by: David Hildenbrand <david@redhat.com>
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index 66d7c07dc177..3514697fc2db 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -63,12 +63,15 @@ TEST_GEN_PROGS += thuge-gen TEST_GEN_PROGS += transhuge-stress TEST_GEN_PROGS += uffd-stress TEST_GEN_PROGS += uffd-unit-tests -TEST_GEN_PROGS += soft-dirty TEST_GEN_PROGS += split_huge_page_test TEST_GEN_PROGS += ksm_tests TEST_GEN_PROGS += ksm_functional_tests TEST_GEN_PROGS += mdwe_test +ifneq ($(ARCH),arm64) +TEST_GEN_PROGS += soft-dirty +endif + ifeq ($(ARCH),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_32bit_program.c -m32) CAN_BUILD_X86_64 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_64bit_program.c) diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index 60547245e479..17bcb07f19f3 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -264,14 +264,35 @@ static void test_softdirty(void) munmap(addr, SIZE); } +static int system_has_softdirty(void) +{ + /* + * There is no way to check if the kernel supports soft-dirty, other + * than by writing to a page and seeing if the bit was set. But the + * tests are intended to check that the bit gets set when it should, so + * doing that check would turn a potentially legitimate fail into a + * skip. Fortunately, we know for sure that arm64 does not support + * soft-dirty. So for now, let's just use the arch as a corse guide. + */ +#if defined(__aarch64__) + return 0; +#else + return 1; +#endif +} + int main(int argc, char **argv) { + int nr_tests = 16; int err; pagesize = getpagesize(); + if (system_has_softdirty()) + nr_tests += 5; + ksft_print_header(); - ksft_set_plan(21); + ksft_set_plan(nr_tests); sense_support(); test_prot_read(); @@ -279,7 +300,8 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - test_softdirty(); + if (system_has_softdirty()) + test_softdirty(); err = ksft_get_fail_cnt(); if (err) diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 3f26f6e15b2a..9e4338aa5e09 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -290,7 +290,10 @@ then CATEGORY="pkey" run_test ./protection_keys_64 fi -CATEGORY="soft_dirty" run_test ./soft-dirty +if [ -x ./soft-dirty ] +then + CATEGORY="soft_dirty" run_test ./soft-dirty +fi # COW tests CATEGORY="cow" run_test ./cow
arm64 does not support the soft-dirty PTE bit. However, the `soft-dirty` test suite is currently run unconditionally and therefore generates spurious test failures on arm64. There are also some tests in `madv_populate` which assume it is supported. For `soft-dirty` lets disable the whole suite for arm64; it is no longer built and run_vmtests.sh will skip it if its not present. For `madv_populate`, we need a runtime mechanism so that the remaining tests continue to be run. Unfortunately, the only way to determine if the soft-dirty dirty bit is supported is to write to a page, then see if the bit is set in /proc/self/pagemap. But the tests that we want to conditionally execute are testing precicesly this. So if we introduced this feature check, we could accedentally turn a real failure (on a system that claims to support soft-dirty) into a skip. So instead, do the check based on architecture; for arm64, we report that soft-dirty is not supported. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- tools/testing/selftests/mm/Makefile | 5 ++++- tools/testing/selftests/mm/madv_populate.c | 26 ++++++++++++++++++++-- tools/testing/selftests/mm/run_vmtests.sh | 5 ++++- 3 files changed, 32 insertions(+), 4 deletions(-)