Re: [PATCH][v3] rtnetlink: add rtnl_lock debug log

On Wed, May 12, 2021 at 1:38 AM Rocco.Yue [off-list ref] wrote:

On Tue, 2021-05-11 at 10:00 -0700, Cong Wang wrote:

quoted

On Tue, May 11, 2021 at 4:46 AM Rocco yue [off-list ref] wrote:

quoted

From: Rocco Yue <redacted>

We often encounter system hangs caused by certain process
holding rtnl_lock for a long time. Even if there is a lock
detection mechanism in Linux, it is a bit troublesome and
affects the system performance. We hope to add a lightweight
debugging mechanism for detecting rtnl_lock.

Any reason why this is specific to RTNL lock? To me holding
a mutex lock for a long time is problematic for any mutex.
I have seen some fs mutex being held for a long time caused
many hung tasks in the system.

Thanks.

Thank you for a good question.

It's a problem to hold rtnl_lock for a long time, and other locks are no
exception.

Then please try to make it generic so that other mutex locks will
benefit too.

Thanks.