On 7/21/22 03:17, yuxin.ye wrote:
On Wed, Jul 20, 2022 at 10:25:17PM -0400, Waiman Long wrote:
On 7/20/22 03:28, yuxin.ye wrote:
before rt_mutex_adjust_prio_chain(),unlock lock->wait_lock will cause
BUG_ON at kernel/locking/rtmutex.c:1331:
The current upstream kernel/locking/rtmutex.c has no BUG_ON() call. Which
version of the kernel are you using?
Cheers,
Longman
The Linux version is 5.10.
The upstream has indeed removed the BUG_ON, But in rt_mutex_adjust_prio_chain()
it is still possible to have a thread is blocked by two locks. Can this situation
be ignored without BUG_ON?
No. However, we don't remove the lock like what you do with your patch.
It will corrupt the data if multiple CPUs are allowed to run
rt_mutex_adjust_prio_chain() for the same rt_mutex simultaneously. You
need to find a way to fix the underlying problem.
BTW, I still can't see a BUG_ON at line 1331 of rtmutex.c with a v5.10
kernel. Does your source tree have some out-of-tree patches that
modifies rtmutex?
Cheers,
Longman
