On Tue, Jun 04, 2024 at 06:30:49AM -1000, Tejun Heo wrote: > Hello, Leon. > > On Tue, Jun 04, 2024 at 02:38:34PM +0300, Leon Romanovsky wrote: > > Thanks, it is very rare situation where call to flush/drain queue > > (in our case kthread_flush_worker) in the middle of the allocation > > flow can be correct. I can't remember any such case. > > > > So even we don't fully understand the root cause, the reimplementation > > is still valid and improves existing code. > > It's not valid. pwq release is async and while wq free in the error path > isn't. The flush is there so that we finish the async part before > synchronize error handling. The patch you posted will can lead to double > free after a pwq allocation failure. We can make the error path synchronous > but the pwq free path should be updated first so that it stays synchronous > in the error path. Note that it *needs* to be asynchronous in non-error > paths, so it's going to be a bit subtle one way or the other. But at that point, we didn't add newly created WQ to any list which will execute that asynchronous release. Did I miss something? Anyway, I understand that the lockdep_register_key() corruption comes from something else. Do you have any idea what can cause it? How can we help debug this issue? Thanks > > Thanks. > > -- > tejun >
