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authorRyan Roberts <[email protected]>2024-01-22 12:05:54 +0000
committerAndrew Morton <[email protected]>2024-01-25 23:52:21 -0800
commitd021b442cf312664811783e92b3d5e4548e92a53 (patch)
tree033d6f1afab88e3bef6f9f37c5a3512f565f4067
parent6f9dc684cae638dda0570154509884ee78d0f75c (diff)
selftests/mm: ksm_tests should only MADV_HUGEPAGE valid memory
ksm_tests was previously mmapping a region of memory, aligning the returned pointer to a PMD boundary, then setting MADV_HUGEPAGE, but was setting it past the end of the mmapped area due to not taking the pointer alignment into consideration. Fix this behaviour. Up until commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries"), this buggy behavior was (usually) masked because the alignment difference was always less than PMD-size. But since the mentioned commit, `ksm_tests -H -s 100` started failing. Link: https://lkml.kernel.org/r/[email protected] Fixes: 325254899684 ("selftests: vm: add KSM huge pages merging time test") Signed-off-by: Ryan Roberts <[email protected]> Cc: Pedro Demarchi Gomes <[email protected]> Cc: Shuah Khan <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
-rw-r--r--tools/testing/selftests/mm/ksm_tests.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c
index 380b691d3eb9..b748c48908d9 100644
--- a/tools/testing/selftests/mm/ksm_tests.c
+++ b/tools/testing/selftests/mm/ksm_tests.c
@@ -566,7 +566,7 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
if (map_ptr_orig == MAP_FAILED)
err(2, "initial mmap");
- if (madvise(map_ptr, len + HPAGE_SIZE, MADV_HUGEPAGE))
+ if (madvise(map_ptr, len, MADV_HUGEPAGE))
err(2, "MADV_HUGEPAGE");
pagemap_fd = open("/proc/self/pagemap", O_RDONLY);