nr_hugepages is not set to zero because the file offset has not been reset after read(). Fix that using lseek(). Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Dev Jain <dev.jain@xxxxxxx> --- Merge dependency: https://lore.kernel.org/all/20240513082842.4117782-1-dev.jain@xxxxxxx/ Andrew, does it sound reasonable to have the fixes tag in the above patch too, along with this series? tools/testing/selftests/mm/compaction_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c index 533999b6c284..c5be395f8363 100644 --- a/tools/testing/selftests/mm/compaction_test.c +++ b/tools/testing/selftests/mm/compaction_test.c @@ -107,6 +107,8 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size) goto close_fd; } + lseek(fd, 0, SEEK_SET); + /* Start with the initial condition of 0 huge pages*/ if (write(fd, "0", sizeof(char)) != sizeof(char)) { ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n", -- 2.30.2