On Fri, 2013-10-04 at 16:02 +0200, Manfred Spraul wrote: > On 10/04/2013 03:55 PM, Mike Galbraith wrote: > > On Fri, 2013-10-04 at 13:28 +0200, Sebastian Andrzej Siewior wrote: > >> On 10/04/2013 01:16 PM, Mike Galbraith wrote: > >>> Manfred's race fix also kills loop, and thereby the -rt livelock, so the > >>> only question is does -rt want to use his completion wakeup scheme, and > >>> does it want to do something about spin_unlock_wait() unconditionally > >>> grabbing/releasing every lock in the array. > >> So his patches went into v3.11 or so right? So all -RT released post > >> this point will have it fixed right? > > Most fixes have gone into master. There's still at least one in the > > pipe, ipc/sem.c: synchronize semop and semctl with IPC_RMID, and I > > _think_ there's still one open issue. > > > > <quoting Manfred> > > And now new: > > 1) ipc/namespace.c: > > free_ipcs() still assumes the "old style" free calls: > > rcu_lock and ipc_lock dropped within the callback. > > > > freeary() was converted - but free_ipcs was not updated. > > > > Thus: > > Closing a namespace with sem arrays and threads that are waiting > > on > > the array with semtimedop() and bad timing can deadlock the semtimedop > > thread. > > (i.e.: spin_lock() waiting forever). > > </quoting Manfred> > That one was a false alarm, i.e. everything is fixed in -mm. Cool, that works out rather nicely. I looked at fixing it, and couldn't figure out what the heck was wrong with it :) -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html