Running the compaction_test sometimes results in out-of-memory failures. When I debugged this, it turned out that the code to reset the number of hugepages to the initial value is simply broken since we write into an open sysctl file descriptor multiple times without seeking back to the start. Adding the lseek here fixes the problem. Cc: stable@xxxxxxxxxxxxxxx Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Link: https://bugs.linaro.org/show_bug.cgi?id=3145 Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- tools/testing/selftests/vm/compaction_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/vm/compaction_test.c b/tools/testing/selftests/vm/compaction_test.c index a65b016d4c13..1097f04e4d80 100644 --- a/tools/testing/selftests/vm/compaction_test.c +++ b/tools/testing/selftests/vm/compaction_test.c @@ -137,6 +137,8 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size) printf("No of huge pages allocated = %d\n", (atoi(nr_hugepages))); + lseek(fd, 0, SEEK_SET); + if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages)) != strlen(initial_nr_hugepages)) { perror("Failed to write value to /proc/sys/vm/nr_hugepages\n"); -- 2.9.0