From d496cc4f0e012d95af41c041933c473bede0fab6 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 9 Jan 2018 17:26:24 +0100 Subject: [PATCH] kselftest: fix OOM in memory compaction test 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@vger.kernel.org Reported-by: Naresh Kamboju Link: https://bugs.linaro.org/show_bug.cgi?id=3145 Signed-off-by: Arnd Bergmann Signed-off-by: Shuah Khan --- 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 a65b016d4c13a..1097f04e4d80e 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"); -- 2.39.5