| Message ID | 20230724082522.1202616-7-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests/mm fixes for arm64 | expand |
On 24.07.23 10:25, Ryan Roberts wrote: > The `migration` test currently has a number of robustness problems that > cause it to hang and leak resources. > > Timeout: There are 3 tests, which each previously ran for 60 seconds. > However, the timeout in mm/settings for a single test binary was set to > 45 seconds. So when run using run_kselftest.sh, the top level timeout > would trigger before the test binary was finished. Solve this by meeting > in the middle; each of the 3 tests now runs for 20 seconds (for a total > of 60), and the top level timeout is set to 90 seconds. > > Leaking child processes: the `shared_anon` test fork()s some children > but then an ASSERT() fires before the test kills those children. The > assert causes immediate exit of the parent and leaking of the children. > Furthermore, if run using the run_kselftest.sh wrapper, the wrapper > would get stuck waiting for those children to exit, which never happens. > Solve this by setting the "parent death signal" to SIGHUP in the child, > so that the child is killed automatically if the parent dies. > > With these changes, the test binary now runs to completion on arm64, > with 2 tests passing and the `shared_anon` test failing. > > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c index 379581567f27..6908569ef406 100644 --- a/tools/testing/selftests/mm/migration.c +++ b/tools/testing/selftests/mm/migration.c @@ -10,12 +10,13 @@ #include <numa.h> #include <numaif.h> #include <sys/mman.h> +#include <sys/prctl.h> #include <sys/types.h> #include <signal.h> #include <time.h> #define TWOMEG (2<<20) -#define RUNTIME (60) +#define RUNTIME (20) #define ALIGN(x, a) (((x) + (a - 1)) & (~((a) - 1))) @@ -155,10 +156,15 @@ TEST_F_TIMEOUT(migration, shared_anon, 2*RUNTIME) memset(ptr, 0xde, TWOMEG); for (i = 0; i < self->nthreads - 1; i++) { pid = fork(); - if (!pid) + if (!pid) { + prctl(PR_SET_PDEATHSIG, SIGHUP); + /* Parent may have died before prctl so check now. */ + if (getppid() == 1) + kill(getpid(), SIGHUP); access_mem(ptr); - else + } else { self->pids[i] = pid; + } } ASSERT_EQ(migrate(ptr, self->n1, self->n2), 0); diff --git a/tools/testing/selftests/mm/settings b/tools/testing/selftests/mm/settings index 9abfc60e9e6f..ba4d85f74cd6 100644 --- a/tools/testing/selftests/mm/settings +++ b/tools/testing/selftests/mm/settings @@ -1 +1 @@ -timeout=45 +timeout=90
The `migration` test currently has a number of robustness problems that cause it to hang and leak resources. Timeout: There are 3 tests, which each previously ran for 60 seconds. However, the timeout in mm/settings for a single test binary was set to 45 seconds. So when run using run_kselftest.sh, the top level timeout would trigger before the test binary was finished. Solve this by meeting in the middle; each of the 3 tests now runs for 20 seconds (for a total of 60), and the top level timeout is set to 90 seconds. Leaking child processes: the `shared_anon` test fork()s some children but then an ASSERT() fires before the test kills those children. The assert causes immediate exit of the parent and leaking of the children. Furthermore, if run using the run_kselftest.sh wrapper, the wrapper would get stuck waiting for those children to exit, which never happens. Solve this by setting the "parent death signal" to SIGHUP in the child, so that the child is killed automatically if the parent dies. With these changes, the test binary now runs to completion on arm64, with 2 tests passing and the `shared_anon` test failing. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- tools/testing/selftests/mm/migration.c | 12 +++++++++--- tools/testing/selftests/mm/settings | 2 +- 2 files changed, 10 insertions(+), 4 deletions(-)