On Mon, Oct 9, 2017 at 11:08 PM, Tejun Heo <[email protected]> wrote: > Hello, > > On Mon, Oct 09, 2017 at 11:02:34PM +0800, Lai Jiangshan wrote: >> I was also thinking alternative code when reviewing. >> The first is quite obvious. Testing POOL_MANAGER_ACTIVE >> can be replaced by testing pool->manager. >> And POOL_MANAGER_ACTIVE is not needed. Isn't it? > > put_unbound_pool() doesn't have to be called from a kworker context > and we don't really have a kworker pointer to set pool->manager to. > We can use a bogus value and then update pool->manager dereferences > accordingly but I think it's cleaner to simply use a separate flag. > >> The second thing is to make manage_workers() >> and put_unbound_pool() exclusive. >> Waiting event on POOL_MANAGER_ACTIVE(or pool->manager) >> is one way. However, the pool's refcnt is not possible to >> be dropped to zero now since the caller still hold the pool->lock > > wait_event_lock_irq() drops the lock if the condition is not met > before going to sleep (otherwise it wouldn't be able to sleep).
I think just using get_pwq()/put_pwq() in manage_workers() as the following said is simpler than using wait_event_lock_irq() thanks Lai > >> and some pwds of the works in the worklist. So the other way >> to enforce the exclusive could be just doing >> get_pwq(the first pwd of the worklist) and put_pwq() when >> the manage_workers() done. And the code about >> pool->manager_arb in put_unbound_pool() can be >> simply removed. > > Yeah, that part is removed. > > Thanks! > > -- > tejun
