On Tue, Jul 31, 2018 at 12:15:37AM -0300, Rafael David Tinoco wrote:
Hello Shuah,
On Mon, Jul 30, 2018 at 05:32:30PM -0600, Shuah Khan wrote:
Hi Rafael,
On 07/30/2018 10:05 AM, Rafael David Tinoco wrote:
Makes membarrier_test compatible with older kernels (LTS) by checking if the membarrier features exist before running the tests.
Link: https://bugs.linaro.org/show_bug.cgi?id=3771 Signed-off-by: Rafael David Tinoco rafael.tinoco@linaro.org Cc: stable@vger.kernel.org #v4.17
.../selftests/membarrier/membarrier_test.c | 69 +++++++++++-------- 1 file changed, 41 insertions(+), 28 deletions(-)
diff --git a/tools/testing/selftests/membarrier/membarrier_test.c b/tools/testing/selftests/membarrier/membarrier_test.c index 6793f8ecc8e7..b96caa096e2f 100644 --- a/tools/testing/selftests/membarrier/membarrier_test.c +++ b/tools/testing/selftests/membarrier/membarrier_test.c @@ -225,7 +225,14 @@ static int test_membarrier_global_expedited_success(void)
static int test_membarrier(void) {
- int status;
- int supported, status;
- supported = sys_membarrier(MEMBARRIER_CMD_QUERY, 0);
- if (supported < 0) {
ksft_test_result_fail("sys_membarrier() failed to query supported cmds\n");return supported;- }
ksft_exit_skip() is the right interface to use here. If feature isn't supported, it should exit skip as opposed fail.
Not sure this is the case here. This part was just a positional change.
This check is extending an existing logic (for MEMBARRIER_CMD_PRIVATE_ EXPEDITED_SYNC_CORE tests). Calling membarrier with MEMBARRIER_CMD_QUERY will return us MEMBARRIER_CMD_BITMASK, telling us which features are enabled for the running kernel (thus which tests can be executed).
The query command was added in v4.3 and should (could ?) be considered a fundament for a working test by now, I suppose, no ?
It is used to decide which further tests to run. Not receiving anything back from this call would mean something is broken (since at least MEMBARRIER_CMD_GLOBAL should have always existed as a membarrier feature/command).
I think your concern is addressed in the beginning of the test. test_membarrier_query() tests for ENOSYS and calls ksft_exit_skip() if CONFIG_MEMBARRIER is disabled.
This part is not about checking if the test can run, but which one can. What do you think ? Tks for reviewing!
Shuah,
Never mind, I'll remove the 2nd MEMBARRIER_CMD_QUERY call, and cache the first call results into a global status. This way, the function test_membarrier_query() will test for availability, and initial issues (like not having MEMBARRIER_CMD_GLOBAL), and skip or return error approprietly like you said. No need to call it twice, just use cached status. Tks for the review.
I'll send a v2.
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