There are timing issues in the use of threads in some selftests for futexes
as the tests rely on timed waits to ensure that the other test thread[s]
reached the lock wait function in the kernel.
That "works" on halfways idle systems, but fails under load which results
in tests failing.
Provide a set of helper functions to create test threads and to wait for
them to reach the lock wait by monitoring /proc/$PID/wchan.
[ tglx: Fixup coding style, move the timeout into the helper, adapt to test
harness changes and massage change log ]
Signed-off-by: Yuwen Chen <ywen.chen@foxmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/tencent_4C90BE98BBC48B38B9FBC6A95C45CF49F309@qq.com
