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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Hi Rafael,

Thanks for the ping.

On 08/09/2018 02:21 PM, 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 | 71 +++++++++++-------- 1 file changed, 40 insertions(+), 31 deletions(-)

diff --git a/tools/testing/selftests/membarrier/membarrier_test.c b/tools/testing/selftests/membarrier/membarrier_test.c index 6793f8ecc8e7..4dc263824bda 100644 --- a/tools/testing/selftests/membarrier/membarrier_test.c +++ b/tools/testing/selftests/membarrier/membarrier_test.c @@ -223,7 +223,7 @@ static int test_membarrier_global_expedited_success(void) return 0; } -static int test_membarrier(void) +static int test_membarrier(int supported) { int status; @@ -236,21 +236,22 @@ static int test_membarrier(void) status = test_membarrier_global_success(); if (status) return status;

• status = test_membarrier_private_expedited_fail();
• if (status)

• return status;
  

• status = test_membarrier_register_private_expedited_success();
• if (status)

• return status;
  

• status = test_membarrier_private_expedited_success();
• if (status)

• return status;
  

• status = sys_membarrier(MEMBARRIER_CMD_QUERY, 0);
• if (status < 0) {

• ksft_test_result_fail("sys_membarrier() failed\n");
  

• return status;
  

• /* commit 22e4ebb975822833b083533035233d128b30e98f added this feature */

Get rid of this comment.

• if (supported & MEMBARRIER_CMD_PRIVATE_EXPEDITED) {

• status = test_membarrier_private_expedited_fail();
  

• if (status)
  

• 	return status;
  

• status = test_membarrier_register_private_expedited_success();
  

• if (status)
  

• 	return status;
  

• status = test_membarrier_private_expedited_success();
  

• if (status)
  

• 	return status;
  

  }

This change moves several tests under this check. These should run to test the case when MEMBARRIER_CMD_PRIVATE_EXPEDITED isn't supported. This change reduces coverage.

• if (status & MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE) {

• /* commit 70216e18e519a54a2f13569e8caff99a092a92d6 added this feature */

Get rid of the above comment.

• if (supported & MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE) { status = test_membarrier_private_expedited_sync_core_fail(); if (status) return status;

@@ -261,23 +262,28 @@ static int test_membarrier(void) if (status) return status; }

• /*

• * It is valid to send a global membarrier from a non-registered
  

• * process.
  

• */
  

• status = test_membarrier_global_expedited_success();
• if (status)

• return status;
  

• status = test_membarrier_register_global_expedited_success();
• if (status)

• return status;
  

• status = test_membarrier_global_expedited_success();
• if (status)

• return status;
  

• /* commit c5f58bd58f432be5d92df33c5458e0bcbee3aadf added this feature */

Get rid of the above comment.

• if (supported & MEMBARRIER_CMD_GLOBAL_EXPEDITED) {

• /*
  

•  * It is valid to send a global membarrier from a non-registered
  

•  * process.
  

•  */
  

• status = test_membarrier_global_expedited_success();
  

• if (status)
  

• 	return status;
  

• status = test_membarrier_register_global_expedited_success();
  

• if (status)
  

• 	return status;
  

• status = test_membarrier_global_expedited_success();
  

• if (status)
  

• 	return status;
  

• }

There skip handling missing here. Without this the test result reports pass which is incorrect.

If feature isn't supported, test should report that the feature test is skipped not passed.

What I would like to see here is a skip for each individual test not one skip for all 3 tests.

This applies to the if (supported & MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE) case above.

When I run this test on 4.19 I see,

TAP version 13 selftests: membarrier: membarrier_test ======================================== ok 1 sys_membarrier available ok 2 sys membarrier invalid command test: command = -1, flags = 0, errno = 22. Failed as expected ok 3 sys membarrier MEMBARRIER_CMD_QUERY invalid flags test: flags = 1, errno = 22. Failed as expected ok 4 sys membarrier MEMBARRIER_CMD_GLOBAL test: flags = 0 ok 5 sys membarrier MEMBARRIER_CMD_PRIVATE_EXPEDITED not registered failure test: flags = 0, errno = 1 ok 6 sys membarrier MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED test: flags = 0 ok 7 sys membarrier MEMBARRIER_CMD_PRIVATE_EXPEDITED test: flags = 0 ok 8 sys membarrier MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE not registered failure test: flags = 0, errno = 1 ok 9 sys membarrier MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE test: flags = 0 ok 10 sys membarrier MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE test: flags = 0 ok 11 sys membarrier MEMBARRIER_CMD_GLOBAL_EXPEDITED test: flags = 0 ok 12 sys membarrier MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED test: flags = 0 ok 13 sys membarrier MEMBARRIER_CMD_GLOBAL_EXPEDITED test: flags = 0 Pass 13 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0 1..13 ok 1..1 selftests: membarrier: membarrier_test [PASS]

A total of 13 tests out of which, maybe 6 should be skips on 4.14. For example, if MEMBARRIER_CMD_GLOBAL_EXPEDITED isn't supported, it should report that test as a skip.

return 0; } -static int test_membarrier_query(void) +static int test_membarrier_query(int *supported) { int flags = 0, ret; @@ -297,16 +303,19 @@ static int test_membarrier_query(void) ksft_exit_skip( "sys_membarrier unsupported: CMD_GLOBAL not found.\n");

• *supported = ret; ksft_test_result_pass("sys_membarrier available\n"); return 0;

} int main(int argc, char **argv) {

• int supported;
• ksft_print_header();

• test_membarrier_query();
• test_membarrier();

• test_membarrier_query(&supported);
• test_membarrier(supported);

return ksft_exit_pass(); }

thanks, -- Shuah