On Fri, Jan 14, 2022 at 03:09:55PM +0100, Peter Zijlstra wrote: > On Tue, Dec 21, 2021 at 05:19:00PM +0000, Peter Oskolkov wrote: > > > + /* > > > + * Workers will still block in umcg_notify_resume() before they can > > > + * consume their error, servers however need to get the error asap. > > > + * > > > + * Still, things might be unrecoverably screwy after this. Not our > > > + * problem. > > > > I think we should explicitly document the unrecoverable screwiness > > of errors here, so that the userspace proactively kills itself > > to avoid badness. The only reason that returning an error here is > > mildly preferable to just killing the task (we already do that > > in other places) is to give the userspace an opportunity to > > log an error, with more state/info than we can do here. > > Bah, I should've written a better comment, because I can't quite > remember the case I had in mind. Also, again from the LAZY patch, I > think we can actually do better in some of the cases here. > > Specifically, currently we'll enqueue on ::runnable_workers_ptr and fail > waking ::next_tid and leave it at that. While I think waking > ::server_tid in that case makes sense. > > I'll go prod at this. Is anybody actually planning to use ::next_tid for workers? My current thinking is that much of the problems here stem from that. Let me ponder more..
