diff --git a/tools/testing/selftests/mm/prctl_thp_disable.c b/tools/testing/selftests/mm/prctl_thp_disable.c index fbbce7c9b2f8..84b4a4b345af 100644 --- a/tools/testing/selftests/mm/prctl_thp_disable.c +++ b/tools/testing/selftests/mm/prctl_thp_disable.c @@ -17,6 +17,10 @@ #include "thp_settings.h" #include "vm_util.h" +#ifndef PR_THP_DISABLE_EXCEPT_ADVISED +#define PR_THP_DISABLE_EXCEPT_ADVISED (1 << 1) +#endif + enum thp_collapse_type { THP_COLLAPSE_NONE, THP_COLLAPSE_MADV_NOHUGEPAGE, @@ -175,4 +179,113 @@ TEST_F(prctl_thp_disable_completely, fork) ASSERT_EQ(ret, 0); } +static void prctl_thp_disable_except_madvise_test(struct __test_metadata *const _metadata, + size_t pmdsize, + enum thp_enabled thp_policy) +{ + ASSERT_EQ(prctl(PR_GET_THP_DISABLE, NULL, NULL, NULL, NULL), 3); + + /* tests after prctl overrides global policy */ + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_NONE, pmdsize), 0); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_NOHUGEPAGE, pmdsize), 0); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_HUGEPAGE, pmdsize), + thp_policy == THP_NEVER ? 0 : 1); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_COLLAPSE, pmdsize), 1); + + /* Reset to global policy */ + ASSERT_EQ(prctl(PR_SET_THP_DISABLE, 0, NULL, NULL, NULL), 0); + + /* tests after prctl is cleared, and only global policy is effective */ + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_NONE, pmdsize), + thp_policy == THP_ALWAYS ? 1 : 0); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_NOHUGEPAGE, pmdsize), 0); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_HUGEPAGE, pmdsize), + thp_policy == THP_NEVER ? 0 : 1); + + ASSERT_EQ(test_mmap_thp(THP_COLLAPSE_MADV_COLLAPSE, pmdsize), 1); +} + +FIXTURE(prctl_thp_disable_except_madvise) +{ + struct thp_settings settings; + size_t pmdsize; +}; + +FIXTURE_VARIANT(prctl_thp_disable_except_madvise) +{ + enum thp_enabled thp_policy; +}; + +FIXTURE_VARIANT_ADD(prctl_thp_disable_except_madvise, never) +{ + .thp_policy = THP_NEVER, +}; + +FIXTURE_VARIANT_ADD(prctl_thp_disable_except_madvise, madvise) +{ + .thp_policy = THP_MADVISE, +}; + +FIXTURE_VARIANT_ADD(prctl_thp_disable_except_madvise, always) +{ + .thp_policy = THP_ALWAYS, +}; + +FIXTURE_SETUP(prctl_thp_disable_except_madvise) +{ + if (!thp_available()) + SKIP(return, "Transparent Hugepages not available\n"); + + self->pmdsize = read_pmd_pagesize(); + if (!self->pmdsize) + SKIP(return, "Unable to read PMD size\n"); + + if (prctl(PR_SET_THP_DISABLE, 1, PR_THP_DISABLE_EXCEPT_ADVISED, NULL, NULL)) + SKIP(return, "Unable to set PR_THP_DISABLE_EXCEPT_ADVISED\n"); + + thp_save_settings(); + thp_read_settings(&self->settings); + self->settings.thp_enabled = variant->thp_policy; + self->settings.hugepages[sz2ord(self->pmdsize, getpagesize())].enabled = THP_INHERIT; + thp_write_settings(&self->settings); +} + +FIXTURE_TEARDOWN(prctl_thp_disable_except_madvise) +{ + thp_restore_settings(); +} + +TEST_F(prctl_thp_disable_except_madvise, nofork) +{ + prctl_thp_disable_except_madvise_test(_metadata, self->pmdsize, variant->thp_policy); +} + +TEST_F(prctl_thp_disable_except_madvise, fork) +{ + int ret = 0; + pid_t pid; + + /* Make sure prctl changes are carried across fork */ + pid = fork(); + ASSERT_GE(pid, 0); + + if (!pid) { + prctl_thp_disable_except_madvise_test(_metadata, self->pmdsize, + variant->thp_policy); + return; + } + + wait(&ret); + if (WIFEXITED(ret)) + ret = WEXITSTATUS(ret); + else + ret = -EINVAL; + ASSERT_EQ(ret, 0); +} + TEST_HARNESS_MAIN