[LTP] [PATCH V2] controllers/memcg: Mark testcase_2 as pass when mlock failed

[Dong ZHu]

On Wed, Jun 01, 2016 at 11:36:52AM +0200, Cyril Hrubis wrote:
> Hi!
> This one is much better but not yet 100% right. Comments below.

Thanks for your suggestion.

> Please use tabs only for the indentation. This code mixes tabs and
> spaces.

Fixed it.

> 
> Also I think that it would be far better if we do just exit(2) here and
> print somehing as "Failed to allocate/lock/populate memory" from
> memcg_lib.sh if the memcg_process.c exits with 2 in the test_proc_kill().

I think we should make a judgment of the return value of mlock, because
only EAGAIN is expected. 

Below is the patch:

--8<--

While running "memcg_memsw_limit_in_bytes_test" always reported below error:
"memcg_memsw_limit_in_bytes_test 2 TFAIL : ltpapicmd.c:193: process 3769
is killed by error"

In function mmap_lock2() mlock failed to lock pages with errno EAGAIN,
the "memcg_process" process exit not the oom killer kill it.

Base on the this:
http://marc.info/?l=linux-mm&m=142122902313315&w=2

So mlock failed it is a expect behavior, in this case test should return
PASS.

Signed-off-by: Dong Zhu <bluezhudong@gmail.com>
---
 testcases/kernel/controllers/memcg/functional/memcg_lib.sh    | 5 ++++-
 testcases/kernel/controllers/memcg/functional/memcg_process.c | 8 ++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
index 9b9b0fd..b0dfce0 100755
--- a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
+++ b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
@@ -229,8 +229,11 @@ test_proc_kill()
 	ps -p $pid > /dev/null 2> /dev/null
 	if [ $? -ne 0 ]; then
 		wait $pid
-		if [ $? -eq 1 ]; then
+		ret=$?
+		if [ $ret -eq 1 ]; then
 			result $FAIL "process $pid is killed by error"
+		elif [[ $ret -eq 2 ]]; then
+			result $PASS "Failed to lock memory"
 		else
 			result $PASS "process $pid is killed"
 		fi
diff --git a/testcases/kernel/controllers/memcg/functional/memcg_process.c b/testcases/kernel/controllers/memcg/functional/memcg_process.c
index 3d34394..40c677b 100644
--- a/testcases/kernel/controllers/memcg/functional/memcg_process.c
+++ b/testcases/kernel/controllers/memcg/functional/memcg_process.c
@@ -203,8 +203,12 @@ void mmap_lock2()
 		if (p == MAP_FAILED)
 			err(1, "mmap failed");
 
-		if (mlock(p, memsize) == -1)
-			err(1, "mlock failed");
+		if (mlock(p, memsize) == -1) {
+			if (errno == EAGAIN)
+				exit(2);
+                        else
+				err(1, "mlock failed");
+                }
 	} else {
 		if (munmap(p, memsize) == -1)
 			err(1, "munmap failed");
-- 
2.1.0

-- 
Best Regards,
Dong Zhu