4.15-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
commit 4c1baad223906943b595a887305f2e8124821dad upstream.
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 naresh.kamboju@linaro.org Link: https://bugs.linaro.org/show_bug.cgi?id=3145 Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Shuah Khan shuahkh@osg.samsung.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/testing/selftests/vm/compaction_test.c | 2 ++ 1 file changed, 2 insertions(+)
--- 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_f 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");