On 10/29/21 2:32 AM, Christian Brauner wrote:
On Fri, Oct 29, 2021 at 10:45:28AM +0800, Li Zhijian wrote:
0Day/LKP observed that the kselftest blocks foever since one of the pidfd_wait doesn't terminate in 1 of 30 runs. After digging into the source, we found that it blocks at: ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0);
we can reproduce it by: $ while true; do make run_tests -C pidfd; done
a delay to ensure that the parent can see child process WCONTINUED.
CC: Christian Brauner christian@brauner.io CC: Shuah Khan shuah@kernel.org CC: Philip Li philip.li@intel.com Reported-by: kernel test robot lkp@intel.com Signed-off-by: Li Zhijian lizhijian@cn.fujitsu.com
Not a fan of the usleep() solution but if it fixes it it's fine for a test, I think. Acked-by: Christian Brauner christian.brauner@ubuntu.com
I don't like introducing usleep() which will increase the kselftest run-time. Every little bit adds up if we allow usleep() in tests.
thanks, -- Shuah