On Wed, Nov 09, 2016 at 08:18:08AM -0500, Jeff Layton wrote: > On Tue, 2016-11-08 at 20:27 -0500, J. Bruce Fields wrote: > > On Tue, Nov 08, 2016 at 05:52:21PM -0500, Tejun Heo wrote: > > > > > > Hello, Bruce. > > > > > > On Tue, Nov 08, 2016 at 04:39:11PM -0500, J. Bruce Fields wrote: > > > > > > > > Apologies, just cleaning out old mail and finding some I should have > > > > responded to long ago: > > > > > > > > On Wed, Aug 31, 2016 at 02:23:48AM +0530, Bhaktipriya Shridhar wrote: > > > > > > > > > > The workqueue "callback_wq" queues a single work item &cb->cb_work per > > > > > nfsd4_callback instance and thus, it doesn't require execution ordering. > > > > > > > > What's "execution ordering"? > > > > > > AIUI, it means that jobs are always run in the order queued and are > serialized. > > > > > We definitely do depend on the fact that at most one of these is running > > > > at a time. > > > > > We do? > > > > If there can be multiple cb's and thus cb->cb_work's per callback_wq, > > > it'd need explicit ordering. Is that the case? > > > > These are basically client RPC tasks, and the cb_work just handles the > submission into the client RPC state machine. Just because we're running > several callbacks at the same time doesn't mean that they need to be > strictly ordered. The client state machine can certainly handle running > these in parallel. I'm not worried about the rpc calls themselves, I'm worried about the other stuff in nfsd4_run_cb_work(), especially nfsd4_process_cb_update(). It's been a while since I thought about it and maybe it'd be OK with a little bit of extra locking. --b. > > Yes, there can be multiple cb_work's. > > > > Yes, but each is effectively a separate work unit. I see no reason why > we'd need to order them at all. > > -- > Jeff Layton <jlayton@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
